diff options
Diffstat (limited to '764/CH6')
33 files changed, 1542 insertions, 0 deletions
diff --git a/764/CH6/EX6.1.a/data6_1.sci b/764/CH6/EX6.1.a/data6_1.sci new file mode 100755 index 000000000..bddebc07b --- /dev/null +++ b/764/CH6/EX6.1.a/data6_1.sci @@ -0,0 +1,18 @@ +
+//(Power Screws) Example 6.1
+//Number of starts n
+n = 3
+//Nominal diameter of screw d (mm)
+d = 50
+//Pitch of the screw p (mm)
+p = 8
+//Collar outer diameter Do (mm)
+Do = 100
+//Collar inner diameter Di (mm)
+Di = 65
+//Coefficient of friction mu
+mu = 0.15
+//Load to be raised W (kN)
+W = 15
+//Force applied at radius rad (mm)
+rad = 500
diff --git a/764/CH6/EX6.1.b/result6_1.txt b/764/CH6/EX6.1.b/result6_1.txt new file mode 100755 index 000000000..a846f935b --- /dev/null +++ b/764/CH6/EX6.1.b/result6_1.txt @@ -0,0 +1,65 @@ +-->//(Power Screws) Example 6.1
+
+-->//Number of starts n
+
+-->n = 3
+ n =
+
+ 3.
+
+-->//Nominal diameter of screw d (mm)
+
+-->d = 50
+ d =
+
+ 50.
+
+-->//Pitch of the screw p (mm)
+
+-->p = 8
+ p =
+
+ 8.
+
+-->//Collar outer diameter Do (mm)
+
+-->Do = 100
+ Do =
+
+ 100.
+
+-->//Collar inner diameter Di (mm)
+
+-->Di = 65
+ Di =
+
+ 65.
+
+-->//Coefficient of friction mu
+
+-->mu = 0.15
+ mu =
+
+ 0.15
+
+-->//Load to be raised W (kN)
+
+-->W = 15
+ W =
+
+ 15.
+
+-->//Force applied at radius rad (mm)
+
+-->rad = 500
+ rad =
+
+ 500.
+
+
+Torque required to raise the load(Mtt) = 204644.140833 mm
+
+Torque required to lower the load(Mlt) = 87401.514671 mm
+
+Force at 500mm radius required to raise the load(Pi) = 409.288282 N
+
\ No newline at end of file diff --git a/764/CH6/EX6.1.b/solution6_1.sce b/764/CH6/EX6.1.b/solution6_1.sce new file mode 100755 index 000000000..8ea8a4506 --- /dev/null +++ b/764/CH6/EX6.1.b/solution6_1.sce @@ -0,0 +1,34 @@ +
+//Obtain path of solution file
+path = get_absolute_file_path('solution6_1.sce')
+//Obtain path of data file
+datapath = path + filesep() + 'data6_1.sci'
+//Clear all
+clc
+//Execute the data file
+exec(datapath)
+//Calculate lead of the screw l (mm)
+l = n * p
+//Calculate mean diameter of the screw dm (mm)
+dm = d - (0.5 * p)
+//Calculate lead angle alpha (degree)
+alpha = atand(l/(%pi * dm))
+//Calculate angle of repose fi (degree)
+fi = atand(mu)
+//Torque required to rise the load Mt (N-mm)
+Mt = ((W * 1000 * dm)*(tand(fi + alpha)))/2
+//Torque required to overcome collar friction Mtc (N-mm)
+//Assume uniform wear theory
+Mtc = ((mu * W * 1000)*(Do + Di))/4
+//Total torque required to raise the load Mtt (N-mm)
+Mtt = Mt + Mtc
+//Torque required to lower the load Ml (N-mm)
+Ml = ((W * 1000 * dm)*(tand(fi - alpha)))/2
+//Total torque required to lower the load Mlt (N-mm)
+Mlt = Ml + Mtc
+//Force required to raise the load Pi (N)
+Pi = Mtt/rad
+//Print results
+printf('\nTorque required to raise the load(Mtt) = %f mm\n',Mtt)
+printf('\nTorque required to lower the load(Mlt) = %f mm\n',Mlt)
+printf('\nForce at %dmm radius required to raise the load(Pi) = %f N\n',rad,Pi)
diff --git a/764/CH6/EX6.10.a/data6_10.sci b/764/CH6/EX6.10.a/data6_10.sci new file mode 100755 index 000000000..652f39bcc --- /dev/null +++ b/764/CH6/EX6.10.a/data6_10.sci @@ -0,0 +1,29 @@ +
+//(Power Screws) Example 6.10
+//Refer Fig.6.17 on page 204
+//Yield tensile strength of 30C8 Syt (N/mm2)
+Syt = 400
+//Factor of safety fs
+fs = 3
+//Punched holes diameter d (mm)
+d = 50
+//Mild steel sheet thickness t (mm)
+t = 1.5
+//Ultimate shear strength of the sheet metal Sus (N/mm2)
+Sus = 375
+//Mass density of balls dense (kg/m3)
+dense = 7280
+//Mean radius of balls Rm (mm)
+Rm = 500
+//Assume screw pitch p (mm)
+p = 8
+//Coefficient of friction mu
+mu = 0.15
+//Minimum lead required lmin (mm)
+lmin = 5 * 4
+//Unit bearing pressure Sb (N/mm2)
+Sb = 18
+//Forward stroke displacement fsd (rad)
+fsd = %pi/2
+//Time required for the forward stroke tf (sec)
+tf = 1
diff --git a/764/CH6/EX6.10.b/result6_10.txt b/764/CH6/EX6.10.b/result6_10.txt new file mode 100755 index 000000000..c9327b0fd --- /dev/null +++ b/764/CH6/EX6.10.b/result6_10.txt @@ -0,0 +1,112 @@ +-->//(Power Screws) Example 6.10
+
+-->//Refer Fig.6.17 on page 204
+
+-->//Yield tensile strength of 30C8 Syt (N/mm2)
+
+-->Syt = 400
+ Syt =
+
+ 400.
+
+-->//Factor of safety fs
+
+-->fs = 3
+ fs =
+
+ 3.
+
+-->//Punched holes diameter d (mm)
+
+-->d = 50
+ d =
+
+ 50.
+
+-->//Mild steel sheet thickness t (mm)
+
+-->t = 1.5
+ t =
+
+ 1.5
+
+-->//Ultimate shear strength of the sheet metal Sus (N/mm2)
+
+-->Sus = 375
+ Sus =
+
+ 375.
+
+-->//Mass density of balls dense (kg/m3)
+
+-->dense = 7280
+ dense =
+
+ 7280.
+
+-->//Mean radius of balls Rm (mm)
+
+-->Rm = 500
+ Rm =
+
+ 500.
+
+-->//Assume screw pitch p (mm)
+
+-->p = 8
+ p =
+
+ 8.
+
+-->//Coefficient of friction mu
+
+-->mu = 0.15
+ mu =
+
+ 0.15
+
+-->//Minimum lead required lmin (mm)
+
+-->lmin = 5 * 4
+ lmin =
+
+ 20.
+
+-->//Unit bearing pressure Sb (N/mm2)
+
+-->Sb = 18
+ Sb =
+
+ 18.
+
+-->//Forward stroke displacement fsd (rad)
+
+-->fsd = %pi/2
+ fsd =
+
+ 1.5707963
+
+-->//Time required for the forward stroke tf (sec)
+
+-->tf = 1
+ tf =
+
+ 1.
+
+
+Screw
+
+Nominal diameter of the screw(d) = 50.000000 mm
+
+Core diameter of the screw(dc) = 42.000000 mm
+
+Lead of the screw(l) = 24.000000 mm
+
+Nut
+
+Length of the nut(L) = 72.000000 mm
+
+Mass of each ball(m) = 52.421082 kg
+
+Diameter of each ball(dia) = 239.584467 mm
+
\ No newline at end of file diff --git a/764/CH6/EX6.10.b/solution6_10.sce b/764/CH6/EX6.10.b/solution6_10.sce new file mode 100755 index 000000000..baef0f20f --- /dev/null +++ b/764/CH6/EX6.10.b/solution6_10.sce @@ -0,0 +1,91 @@ +
+//Function to round-up a value such that it is divisible by 10
+function[v] = round_ten(w)
+ v = ceil(w)
+ rem = pmodulo(v,10)
+ if (rem ~= 0) then
+ v = v + (10 - rem)
+ end
+endfunction
+
+//Obtain path of solution file
+path = get_absolute_file_path('solution6_10.sce')
+//Obtain path of data file
+datapath = path + filesep() + 'data6_10.sci'
+//Clear all
+clc
+//Execute the data file
+exec(datapath)
+//Calculate force required to shear the sheet W (N)
+W = (%pi * d * t * Sus)
+//Compressive stress in the screw sigmac (N/mm2)
+sigmac = Syt/fs
+//Core diameter of the screw dc (mm)
+dc = ((4 * W)/(%pi * sigmac))^(1/2)
+dc = ceil(dc)
+//Obtain the correct number of starts for the screw n
+for n = 1:1:%inf
+ //Calculate the lead of the screw l (mm)
+ l = n * p
+ if (l > lmin) then
+ break
+ end
+end
+//Obtain the correct nominal diameter d in multiples of 10 (mm)
+for d = dc:1:%inf
+ d = round_ten(d)
+ //Calculate the mean diameter of the screw dm (mm)
+ dm = d - (0.5 * p)
+ //Calculate the lead angle alpha (degree)
+ alpha = atand(l/(%pi * dm))
+ //Calculate the angle of repose (fi)
+ fi = atand(mu)
+ //Calculate the torque required Mt (N-mm)
+ Mt = (W * dm * tand(fi + alpha))/2
+ //Calculate the new core diameter dcNew (mm)
+ dcNew = d - p
+ //Calculate the stress in the screw CNew (N/mm2)
+ CNew = ((W * 4)/(%pi * (dcNew^2)))
+ //Calculate the torsional stress tau (N/mm2)
+ tau = (16 * Mt)/(%pi * (dcNew^3))
+ //Calculate the maximum shear stress tauMax (N/mm2)
+ tauMax = (((CNew/2)^2) + (tau^2))^(1/2)
+ //Calculate the afctor of safety fsNew
+ fsNew = ((50/100)*Syt)/tauMax
+ if(fsNew > fs)
+ break
+ end
+end
+//Calculate the efficiency of the screw eta (%)
+eta = (tand(alpha)/tand(fi + alpha))*100
+//Calculate the number of threads z
+z = (4 * W)/(%pi * Sb * ((d^2) - (dcNew^2)))
+z = ceil(z)
+//Calculate the length of the nut L (mm)
+L = z * p
+//Calculate the shear stress in the screw tauS (N/mm2)
+to = p/2
+tauS = (W/(%pi * dcNew * to * z))
+//Calculate the shear stress in the nut tauN (N/mm2)
+tauN = (W/(%pi * d * to * z))
+//Calculate the work done by the punch work (J)
+work = (W * (t/2))/1000
+//Work done by balls workB (J)
+workB = work/(eta/100)
+//Calculate the average angular velocity wavg (rad/s)
+wavg = fsd/tf
+//Calculate the maximum angular velocity wmax (rad/s)
+wmax = 2 * wavg
+//Calculate the mass of the one ball m (kg)
+m = ((workB * 2)/(((Rm/1000)^2) * (%pi^2)))/2
+//Calculate the diameter of the ball dia (mm)
+dia = ((m * 6)/(%pi * dense))^(1/3)
+//Print results
+printf('\nScrew\n')
+printf('\nNominal diameter of the screw(d) = %f mm\n',d)
+printf('\nCore diameter of the screw(dcNew) = %f mm\n',dcNew)
+printf('\nLead of the screw(l) = %f mm\n',l)
+printf('\nNut\n')
+printf('\nLength of the nut(L) = %f mm\n',L)
+printf('\nMass of each ball(m) = %f kg\n',m)
+printf('\nDiameter of each ball(dia) = %f mm\n',dia*1000)
diff --git a/764/CH6/EX6.11.a/data6_11.sci b/764/CH6/EX6.11.a/data6_11.sci new file mode 100755 index 000000000..ea74ef059 --- /dev/null +++ b/764/CH6/EX6.11.a/data6_11.sci @@ -0,0 +1,19 @@ +
+//(Power Screws) Example 6.11
+//Refer Fig.6.27 on page 215
+//Force applied by operator P (N)
+P = 100
+//Mean radius R (mm)
+R = 500
+//Coefficient of friction (mu)
+mu = 0.15
+//Nominal diameter of the upper screw dUp (mm)
+dUp = 50
+//Pitch of the upper screw pUp (mm)
+pUp = 12
+//Nominal diameter of the lower screw dLow (mm)
+dLow = 50
+//Pitch of the upper screw pLow (mm)
+pLow = 8
+//Number of starts of both the screws n
+n = 1
diff --git a/764/CH6/EX6.11.b/result6_11.txt b/764/CH6/EX6.11.b/result6_11.txt new file mode 100755 index 000000000..5862265e8 --- /dev/null +++ b/764/CH6/EX6.11.b/result6_11.txt @@ -0,0 +1,65 @@ +-->//(Power Screws) Example 6.11
+
+-->//Refer Fig.6.27 on page 215
+
+-->//Force applied by operator P (N)
+
+-->P = 100
+ P =
+
+ 100.
+
+-->//Mean radius R (mm)
+
+-->R = 500
+ R =
+
+ 500.
+
+-->//Coefficient of friction (mu)
+
+-->mu = 0.15
+ mu =
+
+ 0.15
+
+-->//Nominal diameter of the upper screw dUp (mm)
+
+-->dUp = 50
+ dUp =
+
+ 50.
+
+-->//Pitch of the upper screw pUp (mm)
+
+-->pUp = 12
+ pUp =
+
+ 12.
+
+-->//Nominal diameter of the lower screw dLow (mm)
+
+-->dLow = 50
+ dLow =
+
+ 50.
+
+-->//Pitch of the upper screw pLow (mm)
+
+-->pLow = 8
+ pLow =
+
+ 8.
+
+-->//Number of starts of both the screws n
+
+-->n = 1
+ n =
+
+ 1.
+
+
+Load that can be raised(W) = 6722.752316 N
+
+Efficiency of the screw jack(eta) = 8.559674 percent
+
\ No newline at end of file diff --git a/764/CH6/EX6.11.b/solution6_11.sce b/764/CH6/EX6.11.b/solution6_11.sce new file mode 100755 index 000000000..3c4104da0 --- /dev/null +++ b/764/CH6/EX6.11.b/solution6_11.sce @@ -0,0 +1,40 @@ +
+//Obtain path of solution file
+path = get_absolute_file_path('solution6_11.sce')
+//Obtain path of data file
+datapath = path + filesep() + 'data6_11.sci'
+//Clear all
+clc
+//Execute the data file
+exec(datapath)
+//For upper screw
+//Calculate the lead lUp (mm)
+lUp = n * pUp
+//Calculate the mean diameter dmUp (mm)
+dmUp = dUp - (0.5 * pUp)
+//Calculate the lead angle alphaUp (degree)
+alphaUp = atand(lUp/(%pi * dmUp))
+//Calculate the angle of repose fi (degree)
+fi = atand(mu)
+//Assume the load to be raised 1N W
+W = 1
+//Calculate the torque required Mt1 (N-mm)
+Mt1 = (W * dmUp * tand(alphaUp + fi))/2
+//For lower screw
+//Calculate the lead lLow (mm)
+lLow = n * pLow
+//Calculate the mean diameter dmLow (mm)
+dmLow = dLow - (0.5 * pLow)
+//Calculate the lead angle alphaLow (degree)
+alphaLow = atand(lLow/(%pi * dmLow))
+//Calculate the torque required Mt2 (N-mm)
+Mt2 = (W * dmLow * tand(fi - alphaLow))/2
+//Total external torque required MTotal (N-mm)
+MTotal = P * R
+//Calculate the actual load that can be raised W (N)
+W = MTotal/(Mt1 + Mt2)
+//Calculate the efficiency of the screw jack eta (%)
+eta = ((4 * W)/(2 * %pi * MTotal))*100
+//Print results
+printf('\nLoad that can be raised(W) = %f N\n',W)
+printf('\nEfficiency of the screw jack(eta) = %f percent\n',eta)
diff --git a/764/CH6/EX6.2.a/data6_2.sci b/764/CH6/EX6.2.a/data6_2.sci new file mode 100755 index 000000000..d7097aaf5 --- /dev/null +++ b/764/CH6/EX6.2.a/data6_2.sci @@ -0,0 +1,15 @@ +
+//(Power Screws) Example 6.1
+//Number of threads n
+n = 2
+//Load to be raised W (kN)
+W = 300
+//Nominal diameter of the screw d (mm)
+d = 100
+//Pitch of the screw p (mm)
+p = 12
+//Coefficient of friction at the screw threads mu
+mu = 0.15
+//For ISO Metric Trapezoidal threads theta (degree)
+theta = 15
+//Neglect collar friction
diff --git a/764/CH6/EX6.2.b/result6_2.txt b/764/CH6/EX6.2.b/result6_2.txt new file mode 100755 index 000000000..55a66e83a --- /dev/null +++ b/764/CH6/EX6.2.b/result6_2.txt @@ -0,0 +1,53 @@ +-->//(Power Screws) Example 6.1
+
+-->//Number of threads n
+
+-->n = 2
+ n =
+
+ 2.
+
+-->//Load to be raised W (kN)
+
+-->W = 300
+ W =
+
+ 300.
+
+-->//Nominal diameter of the screw d (mm)
+
+-->d = 100
+ d =
+
+ 100.
+
+-->//Pitch of the screw p (mm)
+
+-->p = 12
+ p =
+
+ 12.
+
+-->//Coefficient of friction at the screw threads mu
+
+-->mu = 0.15
+ mu =
+
+ 0.15
+
+-->//For ISO Metric Trapezoidal threads theta (degree)
+
+-->theta = 15
+ theta =
+
+ 15.
+
+-->//Neglect collar friction
+
+
+Torque required to raise the load(Mt) = 3378.159205 N-m
+
+Torque required to lower the load(Ml) = 1030.685630 N-m
+
+Efficiency of screw(eta) = 33.921302 percent
+
\ No newline at end of file diff --git a/764/CH6/EX6.2.b/solution6_2.sce b/764/CH6/EX6.2.b/solution6_2.sce new file mode 100755 index 000000000..e4acd876b --- /dev/null +++ b/764/CH6/EX6.2.b/solution6_2.sce @@ -0,0 +1,25 @@ +
+//Obtain path of solution file
+path = get_absolute_file_path('solution6_2.sce')
+//Obtain path of data file
+datapath = path + filesep() + 'data6_2.sci'
+//Clear all
+clc
+//Execute the data file
+exec(datapath)
+//Calculate lead of the screw l (mm)
+l = 2 * p
+//Calculate mean diameter dm (mm)
+dm = d - (0.5 * p)
+//Calculate lead angle alpha (degree)
+alpha = atand(l/(%pi * dm))
+//Calculate the torque required to raise the load Mt (N-m)
+Mt = ((W * 1000 * dm)*((mu * secd(theta)) + (tand(alpha))))/(2 * (1 - (mu * secd(theta) * tand(alpha))))
+//Torque required to lower the load Ml (N-m)
+Ml = ((W * 1000 * dm)*((mu * secd(theta)) - (tand(alpha))))/(2 * (1 + (mu * secd(theta) * tand(alpha))))
+//Calculate the efficiency of screw eta (%)
+eta = ((tand(alpha)*(1 - (mu * secd(theta) * tand(alpha))))/((mu * secd(theta)) + tand(alpha)))*100
+//Print results
+printf('\nTorque required to raise the load(Mt) = %f N-m\n',Mt/1000)
+printf('\nTorque required to lower the load(Ml) = %f N-m\n',Ml/1000)
+printf('\nEfficiency of screw(eta) = %f percent\n',eta)
diff --git a/764/CH6/EX6.3.a/data6_3.sci b/764/CH6/EX6.3.a/data6_3.sci new file mode 100755 index 000000000..a094da233 --- /dev/null +++ b/764/CH6/EX6.3.a/data6_3.sci @@ -0,0 +1,23 @@ +
+//(Power Screws) Example 6.3
+//Refer Fig. 6.12 on page 197
+//Number of starts n
+n = 1
+//Nominal diameter of the screw d (mm)
+d = 22
+//Pitch of the screw p (mm)
+p = 5
+//Outer diameter of the friction collar Do (mm)
+Do = 55
+//Inner diameter of the friction collar Di (mm)
+Di = 45
+//Coefficient of friction for thread mu1
+mu1 = 0.15
+//Coefficient of friction for collar mu1
+mu2 = 0.17
+//Force exerted by the machinist P (N)
+P = 125
+//Mean radius at which the force is applied rad (mm)
+rad = 150
+//Length of the handle dist (mm)
+dist = 150
diff --git a/764/CH6/EX6.3.b/result6_3.txt b/764/CH6/EX6.3.b/result6_3.txt new file mode 100755 index 000000000..f16ac4662 --- /dev/null +++ b/764/CH6/EX6.3.b/result6_3.txt @@ -0,0 +1,79 @@ +-->//(Power Screws) Example 6.3
+
+-->//Refer Fig. 6.12 on page 197
+
+-->//Number of starts n
+
+-->n = 1
+ n =
+
+ 1.
+
+-->//Nominal diameter of the screw d (mm)
+
+-->d = 22
+ d =
+
+ 22.
+
+-->//Pitch of the screw p (mm)
+
+-->p = 5
+ p =
+
+ 5.
+
+-->//Outer diameter of the friction collar Do (mm)
+
+-->Do = 55
+ Do =
+
+ 55.
+
+-->//Inner diameter of the friction collar Di (mm)
+
+-->Di = 45
+ Di =
+
+ 45.
+
+-->//Coefficient of friction for thread mu1
+
+-->mu1 = 0.15
+ mu1 =
+
+ 0.15
+
+-->//Coefficient of friction for collar mu1
+
+-->mu2 = 0.17
+ mu2 =
+
+ 0.17
+
+-->//Force exerted by the machinist P (N)
+
+-->P = 125
+ P =
+
+ 125.
+
+-->//Mean radius at which the force is applied rad (mm)
+
+-->rad = 150
+ rad =
+
+ 150.
+
+-->//Length of the handle dist (mm)
+
+-->dist = 150
+ dist =
+
+ 150.
+
+
+Clamping force developed between the jaws(P) = 2868.610857 N
+
+Overall efficiency of clamp(eta) = 12.174763 percent
+
\ No newline at end of file diff --git a/764/CH6/EX6.3.b/solution6_3.sce b/764/CH6/EX6.3.b/solution6_3.sce new file mode 100755 index 000000000..b50d7d732 --- /dev/null +++ b/764/CH6/EX6.3.b/solution6_3.sce @@ -0,0 +1,33 @@ +
+//Obtain path of solution file
+path = get_absolute_file_path('solution6_3.sce')
+//Obtain path of data file
+datapath = path + filesep() + 'data6_3.sci'
+//Clear all
+clc
+//Execute the data file
+exec(datapath)
+//Calculate lead of the screw l (mm)
+l = n * p
+//Calculate the mean diameter of the screw dm (mm)
+dm = d - (0.5 * p)
+//Calculate the lead angle alpha (degree)
+alpha = atand(l/(%pi * dm))
+//Assume the clamping force to be 1N W
+W = 1
+//Calculate angle of repose for the thread fi1 (degree)
+fi1 = atand(mu1)
+//Calculate torque required Mt (N-mm)
+Mt = (W * dm * tand(fi1 + alpha))/2
+//Calculate torque required to overcome collar friction Mtc (N-mm)
+//Apply uniform-wear theory
+Mtc = ((mu2 * W)*(Do + Di))/4
+//Total external torque applied to the handle MTotal (N-mm)
+MTotal = P * dist
+//Calculate the actual clampng force W (N)
+W = MTotal/(Mt + Mtc)
+//Calculate overall efficiency of the clamp eta (%)
+eta = ((W * l)/(2 * %pi * MTotal))*100
+//Print results
+printf('\nClamping force developed between the jaws(P) = %f N\n',W)
+printf('\nOverall efficiency of clamp(eta) = %f percent\n',eta)
diff --git a/764/CH6/EX6.4.a/data6_4.sci b/764/CH6/EX6.4.a/data6_4.sci new file mode 100755 index 000000000..26442fd32 --- /dev/null +++ b/764/CH6/EX6.4.a/data6_4.sci @@ -0,0 +1,25 @@ +
+//(Power Screws) Example 6.4
+//Refer Fig. 6.13 on page 198
+//Number of starts of the screw n
+n = 1
+//Outer diameter of the screw d (mm)
+d = 40
+//Pitch of the screw p (mm)
+p = 7
+//Weight of the gate w (kN)
+w = 5
+//Frictional resistance in axial direction fr (kN)
+fr = 2
+//Inner diameter of the thrust washer Di (mm)
+Di = 40
+//Outer diameter of the thrust washer Do (mm)
+Do = 80
+//Coefficient of friction at the threads mu1
+mu1 = 0.15
+//Coefficient of friction at the washer mu2
+mu2 = 0.12
+//Radius at which the force is exerted rad (mm)
+rad = 500
+//Permissible bearing pressure Sb (N/mm2)
+Sb = 5
diff --git a/764/CH6/EX6.4.b/result6_4.txt b/764/CH6/EX6.4.b/result6_4.txt new file mode 100755 index 000000000..d4b76cae9 --- /dev/null +++ b/764/CH6/EX6.4.b/result6_4.txt @@ -0,0 +1,90 @@ +-->//(Power Screws) Example 6.4
+
+-->//Refer Fig. 6.13 on page 198
+
+-->//Number of starts of the screw n
+
+-->n = 1
+ n =
+
+ 1.
+
+-->//Outer diameter of the screw d (mm)
+
+-->d = 40
+ d =
+
+ 40.
+
+-->//Pitch of the screw p (mm)
+
+-->p = 7
+ p =
+
+ 7.
+
+-->//Weight of the gate w (kN)
+
+-->w = 5
+ w =
+
+ 5.
+
+-->//Frictional resistance in axial direction fr (kN)
+
+-->fr = 2
+ fr =
+
+ 2.
+
+-->//Inner diameter of the thrust washer Di (mm)
+
+-->Di = 40
+ Di =
+
+ 40.
+
+-->//Outer diameter of the thrust washer Do (mm)
+
+-->Do = 80
+ Do =
+
+ 80.
+
+-->//Coefficient of friction at the threads mu1
+
+-->mu1 = 0.15
+ mu1 =
+
+ 0.15
+
+-->//Coefficient of friction at the washer mu2
+
+-->mu2 = 0.12
+ mu2 =
+
+ 0.12
+
+-->//Radius at which the force is exerted rad (mm)
+
+-->rad = 500
+ rad =
+
+ 500.
+
+-->//Permissible bearing pressure Sb (N/mm2)
+
+-->Sb = 5
+ Sb =
+
+ 5.
+
+
+Maximum force exerted by each arm when the gate is being raised(P1) = 52.410253 N
+
+Maximum force exerted by each arm when the gate is being lowered(P2) = 15.626055 N
+
+Efficiency of the gate mechanism(eta) = 14.879898 percent
+
+Length of the nut(L) = 28.000000 mm
+
\ No newline at end of file diff --git a/764/CH6/EX6.4.b/solution6_4.sce b/764/CH6/EX6.4.b/solution6_4.sce new file mode 100755 index 000000000..1f1379699 --- /dev/null +++ b/764/CH6/EX6.4.b/solution6_4.sce @@ -0,0 +1,51 @@ +
+//Obtain path of solution file
+path = get_absolute_file_path('solution6_4.sce')
+//Obtain path of data file
+datapath = path + filesep() + 'data6_4.sci'
+//Clear all
+clc
+//Execute the data file
+exec(datapath)
+//Calculate the lead of the screw l (mm)
+l = n * p
+//Calculate mean diameter of the screw dm (mm)
+dm = d - (0.5 * p)
+//Calculate the lead angle alpha (degree)
+alpha = atand(l/(%pi * dm))
+//Calculate the angle of repose fi (degree)
+fi = atand(mu1)
+//Axial force on the screw while raising the gate W1 (N)
+W1 = (w * 1000) + (fr *1000)
+//External torque applied to raise the gate Mt (N-mm)
+Mt = ((W1 * dm)*(tand(fi + alpha)))/2
+//Calculate the torque required to overcome washer friction Mtc (N-mm)
+Mtc = (mu2 * W1 * (Do + Di))/4
+//Calculate total torque required to raise the gate Mraise (N-mm)
+Mraise = Mt + Mtc
+//Calculate force exerted by each arm while raising the gate P1 (N)
+P1 = Mraise/(2 * rad)
+//Net axial force on the screw while lowering the gate W2 (N)
+W2 = (w * 1000) - (fr * 1000)
+//External torque applied to lower the gate Ml (N-mm)
+Ml = (W2 * dm * tand(fi - alpha))/2
+//Calculate the torque required to overcome washer friction Mtc (N-mm)
+Mlc = (mu2 * W2 * (Do + Di))/4
+//Calculate total torque required to lower the gate Mlower (N-mm)
+Mlower = Ml + Mlc
+//Calculate force exerted by each arm while lowering the gate P2 (N)
+P2 = Mlower/(2 * rad)
+//Calculate the efficiency of the gate mechanism eta (%)
+eta = (W1 * l)/(2 * %pi * Mraise)
+//Calculate the core diameter of the screw dc (mm)
+dc = d - p
+//Calculate the number of threads z
+z = (4 * W1)/(%pi * Sb * ((d^2) - (dc^2)))
+z = ceil(z)
+//Calculate the length of the nut L (mm)
+L = z * p
+//Print results
+printf('\nMaximum force exerted by each arm when the gate is being raised(P1) = %f N\n',P1)
+printf('\nMaximum force exerted by each arm when the gate is being lowered(P2) = %f N\n',P2)
+printf('\nEfficiency of the gate mechanism(eta) = %f percent\n',eta*100)
+printf('\nLength of the nut(L) = %f mm\n',L)
diff --git a/764/CH6/EX6.5.a/data6_5.sci b/764/CH6/EX6.5.a/data6_5.sci new file mode 100755 index 000000000..0a034ac63 --- /dev/null +++ b/764/CH6/EX6.5.a/data6_5.sci @@ -0,0 +1,19 @@ +
+//(Power Screws) Example 6.5
+//Refer Fig.6.14 on page 199
+//Number of starts on the screw n
+n = 1
+//Nominal diameter of the screw d (mm)
+d = 80
+//Pitch of the screw p (mm)
+p = 10
+//Maximum axial force to be exerted by the screw W (kN)
+W = 10
+//Mean radius of the friction collar rm (mm)
+rm = 30
+//Axial length of the nut L (mm)
+L = 40
+//Coefficient of friction at the threads and collar mu
+mu = 0.12
+//Mean diameter of the rim of the handwheel D (mm)
+D = 500
diff --git a/764/CH6/EX6.5.b/result6_5.txt b/764/CH6/EX6.5.b/result6_5.txt new file mode 100755 index 000000000..afba7364c --- /dev/null +++ b/764/CH6/EX6.5.b/result6_5.txt @@ -0,0 +1,67 @@ +-->//(Power Screws) Example 6.5
+
+-->//Refer Fig.6.14 on page 199
+
+-->//Number of starts on the screw n
+
+-->n = 1
+ n =
+
+ 1.
+
+-->//Nominal diameter of the screw d (mm)
+
+-->d = 80
+ d =
+
+ 80.
+
+-->//Pitch of the screw p (mm)
+
+-->p = 10
+ p =
+
+ 10.
+
+-->//Maximum axial force to be exerted by the screw W (kN)
+
+-->W = 10
+ W =
+
+ 10.
+
+-->//Mean radius of the friction collar rm (mm)
+
+-->rm = 30
+ rm =
+
+ 30.
+
+-->//Axial length of the nut L (mm)
+
+-->L = 40
+ L =
+
+ 40.
+
+-->//Coefficient of friction at the threads and collar mu
+
+-->mu = 0.12
+ mu =
+
+ 0.12
+
+-->//Mean diameter of the rim of the handwheel D (mm)
+
+-->D = 500
+ D =
+
+ 500.
+
+
+Force exerted at the rim to drive the screw(P) = 388.909290 N
+
+Efficiency of the straightner(eta) = 16.369364 percent
+
+Bearing pressure on the threads in the nut(Sb) = 2.122066 N/mm2
+
\ No newline at end of file diff --git a/764/CH6/EX6.5.b/solution6_5.sce b/764/CH6/EX6.5.b/solution6_5.sce new file mode 100755 index 000000000..6e9fe8c30 --- /dev/null +++ b/764/CH6/EX6.5.b/solution6_5.sce @@ -0,0 +1,37 @@ +
+//Obtain path of solution file
+path = get_absolute_file_path('solution6_5.sce')
+//Obtain path of data file
+datapath = path + filesep() + 'data6_5.sci'
+//Clear all
+clc
+//Execute the data file
+exec(datapath)
+//Calculate the lead of the screw l (mm)
+l = n * p
+//Calculate the mean diameter of the screw dm (mm)
+dm = d - (0.5 * p)
+//Calculate the lead angle alpha (degree)
+alpha = atand(l/(%pi * dm))
+//Calculate the angle of repose fi (degree)
+fi = atand(mu)
+//Calculate the torque required Mt (N-mm)
+Mt = ((W * 1000 * dm)*(tand(fi + alpha)))/2
+//Calculate the torque required to overcome the collar friction Mtc (N-mm)
+Mtc = ((mu * W * 1000)*(4 * rm))/4
+//Calculate the total external torque to be applied MTotal (N-mm)
+MTotal = Mt + Mtc
+//Hand force exerted at the hand wheel P (N)
+P = MTotal/(D/2)
+//Calculate the efficiency of the straightner eta (%)
+eta = ((W * 1000 * l)/(2 * %pi * MTotal))*100
+//Calculate the number of threads z
+z = L/p
+//Calculate the core diameter of the screw dc (mm)
+dc = d - p
+//Calculate the bearing pressure on threads in nut Sb (N/mm2)
+Sb = (4 * W * 1000)/(%pi * z * ((d^2) - (dc^2)))
+//Print results
+printf('\nForce exerted at the rim to drive the screw(P) = %f N\n',P)
+printf('\nEfficiency of the straightner(eta) = %f percent\n',eta)
+printf('\nBearing pressure on the threads in the nut(Sb) = %f N/mm2\n',Sb)
diff --git a/764/CH6/EX6.6.a/data6_6.sci b/764/CH6/EX6.6.a/data6_6.sci new file mode 100755 index 000000000..4cf335385 --- /dev/null +++ b/764/CH6/EX6.6.a/data6_6.sci @@ -0,0 +1,22 @@ +
+//(Power Screws) Example 6.6
+//Number of starts n
+n = 1
+//Nominal diameter of the screw d (mm)
+d = 52
+//Pitch of the screw p (mm)
+p = 8
+//Outer diameter of the friction collar Do (mm)
+Do = 100
+//Inner diameter of the friction collar Di (mm)
+Di = 60
+//Coefficient of friction for thread mu1
+mu1 = 0.15
+//Coefficient of friction for collar mu1
+mu2 = 0.12
+//Axial force to be exerted W (kN)
+W = 2
+//Lead screw rpm N
+N = 30
+//For ISO Metric Trapezoidal threads theta (degree)
+theta = 15
diff --git a/764/CH6/EX6.6.b/result6_6.txt b/764/CH6/EX6.6.b/result6_6.txt new file mode 100755 index 000000000..18377f5e8 --- /dev/null +++ b/764/CH6/EX6.6.b/result6_6.txt @@ -0,0 +1,77 @@ +-->//(Power Screws) Example 6.6
+
+-->//Number of starts n
+
+-->n = 1
+ n =
+
+ 1.
+
+-->//Nominal diameter of the screw d (mm)
+
+-->d = 52
+ d =
+
+ 52.
+
+-->//Pitch of the screw p (mm)
+
+-->p = 8
+ p =
+
+ 8.
+
+-->//Outer diameter of the friction collar Do (mm)
+
+-->Do = 100
+ Do =
+
+ 100.
+
+-->//Inner diameter of the friction collar Di (mm)
+
+-->Di = 60
+ Di =
+
+ 60.
+
+-->//Coefficient of friction for thread mu1
+
+-->mu1 = 0.15
+ mu1 =
+
+ 0.15
+
+-->//Coefficient of friction for collar mu1
+
+-->mu2 = 0.12
+ mu2 =
+
+ 0.12
+
+-->//Axial force to be exerted W (kN)
+
+-->W = 2
+ W =
+
+ 2.
+
+-->//Lead screw rpm N
+
+-->N = 30
+ N =
+
+ 30.
+
+-->//For ISO Metric Trapezoidal threads theta (degree)
+
+-->theta = 15
+ theta =
+
+ 15.
+
+
+Power required to drive the lead screw(kW) = 0.061838 kW
+
+Efficiency of the screw(eta) = 12.937099 percent
+
\ No newline at end of file diff --git a/764/CH6/EX6.6.b/solution6_6.sce b/764/CH6/EX6.6.b/solution6_6.sce new file mode 100755 index 000000000..cae3141e7 --- /dev/null +++ b/764/CH6/EX6.6.b/solution6_6.sce @@ -0,0 +1,29 @@ +
+//Obtain path of solution file
+path = get_absolute_file_path('solution6_6.sce')
+//Obtain path of data file
+datapath = path + filesep() + 'data6_6.sci'
+//Clear all
+clc
+//Execute the data file
+exec(datapath)
+//Calculate lead of the screw l (mm)
+l = n * p
+//Calculate the mean diameter of the screw dm (mm)
+dm = d - (0.5 * p)
+//Calculate the lead angle alpha (degree)
+alpha = atand(l/(%pi * dm))
+//Calculate the torque required Mt (N-mm)
+Mt = ((W * 1000 * dm)*((mu1 * secd(theta)) + tand(alpha)))/(2 * (1 - (mu1 * secd(theta) * tand(alpha))))
+//Calculate the torque required to overcome collar friction Mtc (N-mm)
+//Assume uniform-wear theory
+Mtc = ((mu2 * W * 1000)*(Do + Di))/4
+//Calculate total torque required to drive the lead screw MTotal (N-mm)
+MTotal = Mt + Mtc
+//Calculate power required to drive the lead screw kW
+kW = (2 * %pi * N * MTotal)/(60 * (10^6))
+//Calculate efficiency of the screw eta (%)
+eta = ((W * 1000 * l)/(2 * %pi * MTotal))*100
+//Print results
+printf('\nPower required to drive the lead screw(kW) = %f kW\n',kW)
+printf('\nEfficiency of the screw(eta) = %f percent\n',eta)
diff --git a/764/CH6/EX6.7.a/data6_7.sci b/764/CH6/EX6.7.a/data6_7.sci new file mode 100755 index 000000000..23d60dfca --- /dev/null +++ b/764/CH6/EX6.7.a/data6_7.sci @@ -0,0 +1,16 @@ +
+//(Power Screws) Example 6.7
+//Speed of the tool holder v (m/min)
+v = 5
+//Number of starts of the screw n
+n = 1
+//Nominal diameter of the screw d (mm)
+d = 48
+//Pitch of the screw p (mm)
+p = 8
+//Force exerted by operating nut W (N)
+W = 500
+//Mean radius of the friction collar rm (mm)
+rm = 40
+//Coefficient of friction at thread and collar surfaces mu
+mu = 0.15
diff --git a/764/CH6/EX6.7.b/result6_7.txt b/764/CH6/EX6.7.b/result6_7.txt new file mode 100755 index 000000000..b92ae125b --- /dev/null +++ b/764/CH6/EX6.7.b/result6_7.txt @@ -0,0 +1,56 @@ +-->//(Power Screws) Example 6.7
+
+-->//Speed of the tool holder v (m/min)
+
+-->v = 5
+ v =
+
+ 5.
+
+-->//Number of starts of the screw n
+
+-->n = 1
+ n =
+
+ 1.
+
+-->//Nominal diameter of the screw d (mm)
+
+-->d = 48
+ d =
+
+ 48.
+
+-->//Pitch of the screw p (mm)
+
+-->p = 8
+ p =
+
+ 8.
+
+-->//Force exerted by operating nut W (N)
+
+-->W = 500
+ W =
+
+ 500.
+
+-->//Mean radius of the friction collar rm (mm)
+
+-->rm = 40
+ rm =
+
+ 40.
+
+-->//Coefficient of friction at thread and collar surfaces mu
+
+-->mu = 0.15
+ mu =
+
+ 0.15
+
+
+The power required to drive the screw(kW) = 0.347319 kW
+
+Efficiency of the mechanism(eta) = 11.996655 percent
+
\ No newline at end of file diff --git a/764/CH6/EX6.7.b/solution6_7.sce b/764/CH6/EX6.7.b/solution6_7.sce new file mode 100755 index 000000000..ecc077336 --- /dev/null +++ b/764/CH6/EX6.7.b/solution6_7.sce @@ -0,0 +1,32 @@ +
+//Obtain path of solution file
+path = get_absolute_file_path('solution6_7.sce')
+//Obtain path of data file
+datapath = path + filesep() + 'data6_7.sci'
+//Clear all
+clc
+//Execute the data file
+exec(datapath)
+//Calculate lead of the screw l (mm)
+l = n * p
+//Calculate the mean diameter of the screw dm (mm)
+dm = d - (0.5 * p)
+//Calculate the lead angle alpha (degree)
+alpha = atand(l/(%pi * dm))
+//Calculate the angle of repose fi (degree)
+fi = atand(mu)
+//Calculate the torque required Mt (N-mm)
+Mt = (W * dm * tand(fi + alpha))/2
+//Calculate the torque applied to overcome the friction at collar surface Mtc (N-mm)
+Mtc = (mu * W * rm)
+//Calculate the total external torque required MTotal (N-mm)
+MTotal = Mt + Mtc
+//Calculate the rpm of the screw N
+N = (v * 1000)/p
+//Calculate the power required to drive the screw kW
+kW = (2 * %pi * N * MTotal)/(60 * (10^6))
+//Calculate the efficiency of the mechanism eta (%)
+eta = ((W * l)/(2 * %pi * MTotal))*100
+//Print results
+printf('\nThe power required to drive the screw(kW) = %f kW\n',kW)
+printf('\nEfficiency of the mechanism(eta) = %f percent\n',eta)
diff --git a/764/CH6/EX6.8.a/data6_8.sci b/764/CH6/EX6.8.a/data6_8.sci new file mode 100755 index 000000000..3e1f2cd8a --- /dev/null +++ b/764/CH6/EX6.8.a/data6_8.sci @@ -0,0 +1,27 @@ +
+//(Power Screws) Example 6.8
+//Refer Fig.6.15 on page 202
+//Maximum force exerted by the clamp W (kN)
+W = 5
+//Force exerted by the operator F (N)
+F = 250
+//Yield tensile strength of 45C8 Syt (N/mm2)
+Syt = 330
+//Outer diameter of the collar Do (mm)
+Do = 17
+//Inner diameter of the collar Di (mm)
+Di = 6
+//Factor of safety fs
+fs = 2
+//Number of starts of the screw n
+n = 2
+//Coefficient of friction at threads mu1
+mu1 = 0.15
+//Coefficient of friction at collar mu2
+mu2 = 0.17
+//Distance between the handwheel and the frame-top dist (mm)
+dist = 275
+//Assume screw pitch p (mm)
+p = 5
+//Unit bearing pressure Sb (N/mm2)
+Sb = 15
diff --git a/764/CH6/EX6.8.b/result6_8.txt b/764/CH6/EX6.8.b/result6_8.txt new file mode 100755 index 000000000..d30a98614 --- /dev/null +++ b/764/CH6/EX6.8.b/result6_8.txt @@ -0,0 +1,103 @@ +-->//(Power Screws) Example 6.8
+
+-->//Refer Fig.6.15 on page 202
+
+-->//Maximum force exerted by the clamp W (kN)
+
+-->W = 5
+ W =
+
+ 5.
+
+-->//Force exerted by the operator F (N)
+
+-->F = 250
+ F =
+
+ 250.
+
+-->//Yield tensile strength of 45C8 Syt (N/mm2)
+
+-->Syt = 330
+ Syt =
+
+ 330.
+
+-->//Outer diameter of the collar Do (mm)
+
+-->Do = 17
+ Do =
+
+ 17.
+
+-->//Inner diameter of the collar Di (mm)
+
+-->Di = 6
+ Di =
+
+ 6.
+
+-->//Factor of safety fs
+
+-->fs = 2
+ fs =
+
+ 2.
+
+-->//Number of starts of the screw n
+
+-->n = 2
+ n =
+
+ 2.
+
+-->//Coefficient of friction at threads mu1
+
+-->mu1 = 0.15
+ mu1 =
+
+ 0.15
+
+-->//Coefficient of friction at collar mu2
+
+-->mu2 = 0.17
+ mu2 =
+
+ 0.17
+
+-->//Distance between the handwheel and the frame-top dist (mm)
+
+-->dist = 275
+ dist =
+
+ 275.
+
+-->//Assume screw pitch p (mm)
+
+-->p = 5
+ p =
+
+ 5.
+
+-->//Unit bearing pressure Sb (N/mm2)
+
+-->Sb = 15
+ Sb =
+
+ 15.
+
+
+Screw
+
+Nominal diameter of the screw(d) = 22.000000 mm
+
+Core diameter of the screw(dcNew) = 17.000000 mm
+
+Nut
+
+Length of the nut(L) = 15.000000 mm
+
+Number of threads(z) = 3.000000
+
+Radius of the ball hand(Rm) = 82.164119 mm
+
\ No newline at end of file diff --git a/764/CH6/EX6.8.b/solution6_8.sce b/764/CH6/EX6.8.b/solution6_8.sce new file mode 100755 index 000000000..65238123e --- /dev/null +++ b/764/CH6/EX6.8.b/solution6_8.sce @@ -0,0 +1,71 @@ +
+//Obtain path of solution file
+path = get_absolute_file_path('solution6_8.sce')
+//Obtain path of data file
+datapath = path + filesep() + 'data6_8.sci'
+//Clear all
+clc
+//Execute the data file
+exec(datapath)
+//Compressive stress at the intermediate screw portion sigmac (N/mm2)
+sigmac = Syt/fs
+//Calculate the core diameter of the screw dc (mm)
+dc = ((4 * W * 1000)/(%pi * sigmac))^(1/2)
+//Round-up dc
+dc = ceil(dc)
+//Calculate the angle of repose fi (degree)
+fi = atand(mu1)
+//Calculate lead of the screw l (mm)
+l = n * p
+//Calculate the torque required to overcome collar friction Mtc (N-mm)
+Mtc = ((mu2 * W * 1000)*(Do + Di))/4
+//Calculate the maximum bending moment Mb (N-mm)
+Mb = (F * dist)
+//Obtain the correct value of nominal diameter d (mm)
+for d = dc:1:%inf
+ //Calculate the mean diameter of the screw dm (mm)
+ dm = d - (0.5 * p)
+ //Calculate the lead angle alpha (degree)
+ alpha = atand(l/(%pi * dm))
+ //Calculate the torque required Mt (N-mm)
+ Mt = (W * 1000 * dm * tand(fi + alpha))/2
+ //Calculate the total torque applied MTotal (N-mm)
+ MTotal = Mt + Mtc
+ //Calculate the new core diameter dcNew (mm)
+ dcNew = d - p
+ //Calculate the torsional shear stress at A-A tauA (N/mm2)
+ tauA = (16 * MTotal)/(%pi * (dcNew^3))
+ //Calculate the bending stress due to hand force sigmab (N/mm2)
+ sigmab = (32 * Mb)/(%pi * (dcNew^3))
+ //Calculate the maximum shear stress tauAMax (N/mm2)
+ tauAMax = ((((sigmab/2)^2) + (tauA^2)))^(1/2)
+ //Calculate the factor of safety fsA
+ fsA = ((50/100) * Syt)/tauAMax
+ //Calculate the torsional stress at section B-B tauB (N/mm2)
+ tauB = (16 * Mtc)/(%pi * (dcNew^3))
+ //Calculate the direct compressive stress due to clamping force Comp (N/mm2)
+ Comp = (W * 1000 * 4)/(%pi * (dcNew^2))
+ //Calculate the maximum shear stress tauBMax (N/mm2)
+ tauBMax = (((Comp/2)^2) + (tauB^2))^(1/2)
+ //Calculate the factor of safety fsB
+ fsB = ((50/100)*Syt)/tauBMax
+ //Check the factor of safety condition
+ if(fsB > fs & fsA > fs)
+ break
+ end
+end
+//Calculate the number of threads z
+z = (4 * W * 1000)/(%pi * Sb * ((d^2) - (dcNew^2)))
+z = ceil(z)
+//Calculate the length of the nut L (mm)
+L = z * p
+//Calculate the radius of the ball hand Rm (mm)
+Rm = MTotal/F
+//Print results
+printf('\nScrew\n')
+printf('\nNominal diameter of the screw(d) = %f mm\n',d)
+printf('\nCore diameter of the screw(dcNew) = %f mm\n',dcNew)
+printf('\nNut\n')
+printf('\nLength of the nut(L) = %f mm\n',L)
+printf('\nNumber of threads(z) = %f\n',z)
+printf('\nRadius of the ball hand(Rm) = %f mm\n',Rm)
diff --git a/764/CH6/EX6.9.a/data6_9.sci b/764/CH6/EX6.9.a/data6_9.sci new file mode 100755 index 000000000..53206157c --- /dev/null +++ b/764/CH6/EX6.9.a/data6_9.sci @@ -0,0 +1,19 @@ +
+//(Power Screws) Example 6.9
+//Refer Fig.6.16 on page 203
+//Number of starts on the screw n
+n = 1
+//Nominal diameter of the screw d (mm)
+d = 22
+//Pitch of the screw p (mm)
+p = 5
+//Coeffecient of friction on the threads and collar mu
+mu = 0.15
+//Mean radius of the friction collar rm (mm)
+rm = 15
+//Clamp capacity W (N)
+W = 750
+//Yield tensile strength of 30C8 Syt (N/mm2)
+Syt = 400
+//Force exerted by the operator P (N)
+P = 20
diff --git a/764/CH6/EX6.9.b/result6_9.txt b/764/CH6/EX6.9.b/result6_9.txt new file mode 100755 index 000000000..9037f819b --- /dev/null +++ b/764/CH6/EX6.9.b/result6_9.txt @@ -0,0 +1,67 @@ +-->//(Power Screws) Example 6.9
+
+-->//Refer Fig.6.16 on page 203
+
+-->//Number of starts on the screw n
+
+-->n = 1
+ n =
+
+ 1.
+
+-->//Nominal diameter of the screw d (mm)
+
+-->d = 22
+ d =
+
+ 22.
+
+-->//Pitch of the screw p (mm)
+
+-->p = 5
+ p =
+
+ 5.
+
+-->//Coeffecient of friction on the threads and collar mu
+
+-->mu = 0.15
+ mu =
+
+ 0.15
+
+-->//Mean radius of the friction collar rm (mm)
+
+-->rm = 15
+ rm =
+
+ 15.
+
+-->//Clamp capacity W (N)
+
+-->W = 750
+ W =
+
+ 750.
+
+-->//Yield tensile strength of 30C8 Syt (N/mm2)
+
+-->Syt = 400
+ Syt =
+
+ 400.
+
+-->//Force exerted by the operator P (N)
+
+-->P = 20
+ P =
+
+ 20.
+
+
+Torque required to tighten the clamp(MTotal) = 3402.198556 N-mm
+
+Length of the handle(a) = 170.109928 mm
+
+Diameter of the handle(dh) = 4.424864 mm
+
\ No newline at end of file diff --git a/764/CH6/EX6.9.b/solution6_9.sce b/764/CH6/EX6.9.b/solution6_9.sce new file mode 100755 index 000000000..79cbcd208 --- /dev/null +++ b/764/CH6/EX6.9.b/solution6_9.sce @@ -0,0 +1,33 @@ +
+//Obtain path of solution file
+path = get_absolute_file_path('solution6_9.sce')
+//Obtain path of data file
+datapath = path + filesep() + 'data6_9.sci'
+//Clear all
+clc
+//Execute the data file
+exec(datapath)
+//Calculate the lead of the screw l (mm)
+l = n * p
+//Calculate the mean diameter of the screw dm (mm)
+dm = d - (0.5 * p)
+//Calculate the lead angle alpha (degree)
+alpha = atand(l/(%pi * dm))
+//Calculate the angle of repose fi (degree)
+fi = atand(mu)
+//Calculate the torque required Mt (N-mm)
+Mt = (W * dm * tand(fi + alpha))/2
+//Calculate the torque required to overcome the collar friction Mtc (N-mm)
+Mtc = (mu * W * rm)
+//Calculate the total external torque required MTotal (N-mm)
+MTotal = Mt + Mtc
+//Calculate the length of the handle a (mm)
+a = MTotal/P
+//Calculate the maximum bending moment near the screw Mb (N-mm)
+Mb = P * a
+//Calculate the diameter of the handle dh (mm)
+dh = ((32 * Mb)/(Syt * %pi))^(1/3)
+//Print results
+printf('\nTorque required to tighten the clamp(MTotal) = %f N-mm\n',MTotal)
+printf('\nLength of the handle(a) = %f mm\n',a)
+printf('\nDiameter of the handle(dh) = %f mm\n',dh)
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