diff options
Diffstat (limited to '764/CH12')
39 files changed, 1326 insertions, 0 deletions
diff --git a/764/CH12/EX12.1.a/data12_1.sci b/764/CH12/EX12.1.a/data12_1.sci new file mode 100755 index 000000000..26255bb1f --- /dev/null +++ b/764/CH12/EX12.1.a/data12_1.sci @@ -0,0 +1,14 @@ + +//(Brakes) Example 12.1 +//Diameter of the disk D (m) +D = 1 +//Thickness of the disk t (m) +t = 0.2 +//Speed of the flywheel n1 (rpm) +n1 = 350 +//Time required to bring the disk to rest ts (s) +ts = 1.5 +//Mass density of the disk rho (kg/m3) +rho = 7200 +//Final angular speed of the disk w2 (rad/s) +w2 = 0 diff --git a/764/CH12/EX12.1.b/result12_1.txt b/764/CH12/EX12.1.b/result12_1.txt new file mode 100755 index 000000000..5b8f8a1f3 --- /dev/null +++ b/764/CH12/EX12.1.b/result12_1.txt @@ -0,0 +1,49 @@ +-->//(Brakes) Example 12.1
+
+-->//Diameter of the disk D (m)
+
+-->D = 1
+ D =
+
+ 1.
+
+-->//Thickness of the disk t (m)
+
+-->t = 0.2
+ t =
+
+ 0.2
+
+-->//Speed of the flywheel n1 (rpm)
+
+-->n1 = 350
+ n1 =
+
+ 350.
+
+-->//Time required to bring the disk to rest ts (s)
+
+-->ts = 1.5
+ ts =
+
+ 1.5
+
+-->//Mass density of the disk rho (kg/m3)
+
+-->rho = 7200
+ rho =
+
+ 7200.
+
+-->//Final angular speed of the disk w2 (rad/s)
+
+-->w2 = 0
+ w2 =
+
+ 0.
+
+
+Energy absorbed by the brakes(E) = 94956.722333 J
+
+Torque capacity of the brakes(Mt) = 3454.361540 N-m
+
\ No newline at end of file diff --git a/764/CH12/EX12.1.b/solution12_1.sce b/764/CH12/EX12.1.b/solution12_1.sce new file mode 100755 index 000000000..3120af0a5 --- /dev/null +++ b/764/CH12/EX12.1.b/solution12_1.sce @@ -0,0 +1,24 @@ + +//Obtain path of solution file +path = get_absolute_file_path('solution12_1.sce') +//Obtain path of data file +datapath = path + filesep() + 'data12_1.sci' +//Clear all +clc +//Execute the data file +exec(datapath) +//Calculate the mass of the disk m (kg) +m = (%pi/4)*(D^2 * t * rho) +//Calculate the radius of gyration of the disk k (m) +k = D/sqrt(8) +//Calculatet the initial angular speed of the disk w1 (rad/s) +w1 = (2 * %pi * n1)/60 +//Calculate the energy absorbed by the brakes (J) +E = (1/2)*(m * k^2 * (w1^2 - w2^2)) +//Calculate the average velocity during the braking period wavg (rad/s) +wavg = (w1 + w2)/2 +//Calculate the torque capacity of the brake Mt (N-m) +Mt = E/(wavg * ts) +//Print results +printf("\nEnergy absorbed by the brakes(E) = %f J\n",E) +printf("\nTorque capacity of the brakes(Mt) = %f N-m\n",Mt) diff --git a/764/CH12/EX12.10.a/data12_10.sci b/764/CH12/EX12.10.a/data12_10.sci new file mode 100755 index 000000000..4f5617148 --- /dev/null +++ b/764/CH12/EX12.10.a/data12_10.sci @@ -0,0 +1,20 @@ + +//(Brakes) Example 12.10 +//Width of the steel band w (mm) +w = 100 +//Thickness of the steel band t (mm) +t = 3 +//Maximum tensile stress in the band sigmat (N/mm2) +sigmat = 50 +//Coefficient of friction between the friction lining and the drum mu +mu = 0.25 +//Radius of the drum R (mm) +R = 300 +//Angle of wrap theta (deg) +theta = 240 +//Distance of the loose end from the pivot d1 (mm) +d1 = 200 +//Distance of the tight end from the pivot d2 (mm) +d2 = 50 +//Distance of the force from the loose end d3 (mm) +d3 = 750 diff --git a/764/CH12/EX12.10.b/result12_10.txt b/764/CH12/EX12.10.b/result12_10.txt new file mode 100755 index 000000000..774e9da1f --- /dev/null +++ b/764/CH12/EX12.10.b/result12_10.txt @@ -0,0 +1,76 @@ +-->//(Brakes) Example 12.10
+
+-->//Width of the steel band w (mm)
+
+-->w = 100
+ w =
+
+ 100.
+
+-->//Thickness of the steel band t (mm)
+
+-->t = 3
+ t =
+
+ 3.
+
+-->//Maximum tensile stress in the band sigmat (N/mm2)
+
+-->sigmat = 50
+ sigmat =
+
+ 50.
+
+-->//Coefficient of friction between the friction lining and the drum mu
+
+-->mu = 0.25
+ mu =
+
+ 0.25
+
+-->//Radius of the drum R (mm)
+
+-->R = 300
+ R =
+
+ 300.
+
+-->//Angle of wrap theta (deg)
+
+-->theta = 240
+ theta =
+
+ 240.
+
+-->//Distance of the loose end from the pivot d1 (mm)
+
+-->d1 = 200
+ d1 =
+
+ 200.
+
+-->//Distance of the tight end from the pivot d2 (mm)
+
+-->d2 = 50
+ d2 =
+
+ 50.
+
+-->//Distance of the force from the loose end d3 (mm)
+
+-->d3 = 750
+ d3 =
+
+ 750.
+
+
+The brake is not self-locking
+
+Tension in the band on the tight side(P1) = 15000.000000 N
+
+Tension in the band on the loose side(P2) = 5263.797108 N
+
+Actuating force(P) = 318.694128 N
+
+Torque capacity of the brake(Mt) = 2920.860868 N-m
+
\ No newline at end of file diff --git a/764/CH12/EX12.10.b/solution12_10.sce b/764/CH12/EX12.10.b/solution12_10.sce new file mode 100755 index 000000000..f91e5cd00 --- /dev/null +++ b/764/CH12/EX12.10.b/solution12_10.sce @@ -0,0 +1,28 @@ + +//Obtain path of solution file +path = get_absolute_file_path('solution12_10.sce') +//Obtain path of data file +datapath = path + filesep() + 'data12_10.sci' +//Clear all +clc +//Execute the data file +exec(datapath) +//Calculate the tension in the band on tight side P1 (N) +P1 = sigmat * w * t +//Calculate the tension in the band on the loose side P2 (N) +P2 = P1/(%e^(mu * theta * %pi/180)) +//Calculate the actuating force on the lever P (N) +P = (P2 * d1 - P1 * d2)/(d3 + d1) +//Calculate the torque capacity of the brake Mt (N-m) +Mt = (P1 - P2)*R +//Check self-locking +if ((d1 / d2)>(%e^(mu * theta * %pi/180))) + printf("\nThe brake is not self-locking\n") +else + printf("\nThe brake is self-locking\n") +end +//Print results +printf("\nTension in the band on the tight side(P1) = %f N\n",P1) +printf("\nTension in the band on the loose side(P2) = %f N\n",P2) +printf("\nActuating force(P) = %f N\n",P) +printf("\nTorque capacity of the brake(Mt) = %f N-m\n",Mt/1000) diff --git a/764/CH12/EX12.11.a/result12_11.sce b/764/CH12/EX12.11.a/result12_11.sce new file mode 100755 index 000000000..3b47d037b --- /dev/null +++ b/764/CH12/EX12.11.a/result12_11.sce @@ -0,0 +1,2 @@ +//Example 12.11 from 'Brakes' cannot be coded because almost all the information is obtained from
+//the figure by construction.
diff --git a/764/CH12/EX12.12.a/data12_12.sci b/764/CH12/EX12.12.a/data12_12.sci new file mode 100755 index 000000000..7e19db69b --- /dev/null +++ b/764/CH12/EX12.12.a/data12_12.sci @@ -0,0 +1,14 @@ + +//(Brakes) Example 12.12 +//Troque capacity of the disk brake Mt (N-m) +Mt = 1500 +//Outer radius of the pad Ro (mm) +Ro = 150 +//Inner radius of the pad Ri (mm) +Ri = 100 +//Coefficient of friction mu +mu = 0.35 +//Average pressure on the pad pavg (MPa) +pavg = 2 +//Number of pads n +n = 2 diff --git a/764/CH12/EX12.12.b/result12_12.txt b/764/CH12/EX12.12.b/result12_12.txt new file mode 100755 index 000000000..a3917c001 --- /dev/null +++ b/764/CH12/EX12.12.b/result12_12.txt @@ -0,0 +1,47 @@ +-->//(Brakes) Example 12.12
+
+-->//Troque capacity of the disk brake Mt (N-m)
+
+-->Mt = 1500
+ Mt =
+
+ 1500.
+
+-->//Outer radius of the pad Ro (mm)
+
+-->Ro = 150
+ Ro =
+
+ 150.
+
+-->//Inner radius of the pad Ri (mm)
+
+-->Ri = 100
+ Ri =
+
+ 100.
+
+-->//Coefficient of friction mu
+
+-->mu = 0.35
+ mu =
+
+ 0.35
+
+-->//Average pressure on the pad pavg (MPa)
+
+-->pavg = 2
+ pavg =
+
+ 2.
+
+-->//Number of pads n
+
+-->n = 2
+ n =
+
+ 2.
+
+
+Angular dimension of the pad(theta) = 77.543160 deg
+
\ No newline at end of file diff --git a/764/CH12/EX12.12.b/solution12_12.sce b/764/CH12/EX12.12.b/solution12_12.sce new file mode 100755 index 000000000..8a76cdef1 --- /dev/null +++ b/764/CH12/EX12.12.b/solution12_12.sce @@ -0,0 +1,21 @@ + +//Obtain path of solution file +path = get_absolute_file_path('solution12_12.sce') +//Obtain path of data file +datapath = path + filesep() + 'data12_12.sci' +//Clear all +clc +//Execute the data file +exec(datapath) +//Calculate the torque capacity of each pad mt (N-m) +mt = Mt/n +//Calculate the friction radius Rf (mm) +Rf = (2 * (Ro^3 - Ri^3))/(3 * (Ro^2 - Ri^2)) +//Calculate the actuating force P (N) +P = (mt * 1000)/(mu * Rf) +//Calculate the area of the pad A (mm2) +A = P/pavg +//Calculate the angular dimension of the pad theta (deg) +theta = ((2 * A)/(Ro^2 - Ri^2))*180/%pi +//Print results +printf("\nAngular dimension of the pad(theta) = %f deg\n",theta) diff --git a/764/CH12/EX12.13.a/data12_13.sci b/764/CH12/EX12.13.a/data12_13.sci new file mode 100755 index 000000000..35731d7cd --- /dev/null +++ b/764/CH12/EX12.13.a/data12_13.sci @@ -0,0 +1,14 @@ + +//(Brakes) Example 12.13 +//Troque capacity of the disk brake Mt (N-m) +Mt = 1500 +//Number of caliper brakes on the wheel nb +nb = 3 +//Number of pads on each caliper brake np +np = 2 +//Coefficient of friction mu +mu = 0.35 +//Average pressure on the pad pavg (MPa) +pavg = 2 +//R/e ratio r +r = 0.2 diff --git a/764/CH12/EX12.13.a/table12_13.csv b/764/CH12/EX12.13.a/table12_13.csv new file mode 100755 index 000000000..be520b13a --- /dev/null +++ b/764/CH12/EX12.13.a/table12_13.csv @@ -0,0 +1,8 @@ +Refer Table 12.1 on page 495, +R/e,delta +0,1 +0.1,0.9833 +0.2,0.9693 +0.3,0.9572 +0.4,0.9467 +0.5,0.9375 diff --git a/764/CH12/EX12.13.b/result12_13.txt b/764/CH12/EX12.13.b/result12_13.txt new file mode 100755 index 000000000..78046e7a7 --- /dev/null +++ b/764/CH12/EX12.13.b/result12_13.txt @@ -0,0 +1,47 @@ +-->//(Brakes) Example 12.13
+
+-->//Troque capacity of the disk brake Mt (N-m)
+
+-->Mt = 1500
+ Mt =
+
+ 1500.
+
+-->//Number of caliper brakes on the wheel nb
+
+-->nb = 3
+ nb =
+
+ 3.
+
+-->//Number of pads on each caliper brake np
+
+-->np = 2
+ np =
+
+ 2.
+
+-->//Coefficient of friction mu
+
+-->mu = 0.35
+ mu =
+
+ 0.35
+
+-->//Average pressure on the pad pavg (MPa)
+
+-->pavg = 2
+ pavg =
+
+ 2.
+
+-->//R/e ratio r
+
+-->r = 0.2
+ r =
+
+ 0.2
+
+
+Radius of the pad(R) = 28.625602 mm
+
\ No newline at end of file diff --git a/764/CH12/EX12.13.b/solution12_13.sce b/764/CH12/EX12.13.b/solution12_13.sce new file mode 100755 index 000000000..57eb6595d --- /dev/null +++ b/764/CH12/EX12.13.b/solution12_13.sce @@ -0,0 +1,24 @@ + +//Obtain path of solution file +path = get_absolute_file_path('solution12_13.sce') +//Obtain path of data file +datapath = path + filesep() + 'data12_13.sci' +//Clear all +clc +//Execute the data file +exec(datapath) +//Calculate the torque capacity of one pad mt (N-m) +mt = Mt/(nb * np) +//Read the csv file containing table 12.1 +numeric = read_csv(path + filesep() + 'table12_13.csv') +//Obtain the value of delta +for row = 3:1:%inf + if (evstr(numeric(row,1)) == r) + delta = evstr(numeric(row,2)) + break + end +end +//Calculate the radius of the pad R (mm) +R = (mt * 1000/(mu * pavg * %pi * (delta/r)))^(1/3) +//Print results +printf("\nRadius of the pad(R) = %f mm\n",R) diff --git a/764/CH12/EX12.14.a/data12_14.sci b/764/CH12/EX12.14.a/data12_14.sci new file mode 100755 index 000000000..57e133519 --- /dev/null +++ b/764/CH12/EX12.14.a/data12_14.sci @@ -0,0 +1,14 @@ + +//(Brakes) Example 12.14 +//Mass of the flywheel M (kg) +M = 100 +//Radius of gyration of the flywheel k (mm) +k = 350 +//Speed of the flywheel n (rpm) +n = 500 +//Mass of the brake drum m (kg) +m = 5 +//Specific heat capacity of the brake drum c (J/kgK) +c = 460 +//Final velocity of the flywheel w2 (rad/s) +w2 = 0 diff --git a/764/CH12/EX12.14.b/result12_14.txt b/764/CH12/EX12.14.b/result12_14.txt new file mode 100755 index 000000000..66a403cdb --- /dev/null +++ b/764/CH12/EX12.14.b/result12_14.txt @@ -0,0 +1,49 @@ +-->//(Brakes) Example 12.14
+
+-->//Mass of the flywheel M (kg)
+
+-->M = 100
+ M =
+
+ 100.
+
+-->//Radius of gyration of the flywheel k (mm)
+
+-->k = 350
+ k =
+
+ 350.
+
+-->//Speed of the flywheel n (rpm)
+
+-->n = 500
+ n =
+
+ 500.
+
+-->//Mass of the brake drum m (kg)
+
+-->m = 5
+ m =
+
+ 5.
+
+-->//Specific heat capacity of the brake drum c (J/kgK)
+
+-->c = 460
+ c =
+
+ 460.
+
+-->//Final velocity of the flywheel w2 (rad/s)
+
+-->w2 = 0
+ w2 =
+
+ 0.
+
+
+Temperature rise of the brake drum(t) = 7.300885 deg celsius
+
+The printed answer is erroneous
+
\ No newline at end of file diff --git a/764/CH12/EX12.14.b/solution12_14.sce b/764/CH12/EX12.14.b/solution12_14.sce new file mode 100755 index 000000000..8142093ed --- /dev/null +++ b/764/CH12/EX12.14.b/solution12_14.sce @@ -0,0 +1,18 @@ + +//Obtain path of solution file +path = get_absolute_file_path('solution12_14.sce') +//Obtain path of data file +datapath = path + filesep() + 'data12_14.sci' +//Clear all +clc +//Execute the data file +exec(datapath) +//Calculate the initial angular velocity of the flywheel w1 (rad/s) +w1 = (2 * %pi * n)/60 +//Calculate the KE of the flywheel KE (J) +KE = 0.5 * M * (k/1000)^2 * (w1^2 - w2^2) +//Calculate the temperature rise of the drum t (deg celsius) +t = KE/(m * c) +//Print results +printf("\nTemperature rise of the brake drum(t) = %f deg celsius\n",t) +printf("\nThe printed answer is erroneous\n") diff --git a/764/CH12/EX12.2.a/data12_2.sci b/764/CH12/EX12.2.a/data12_2.sci new file mode 100755 index 000000000..4d113a906 --- /dev/null +++ b/764/CH12/EX12.2.a/data12_2.sci @@ -0,0 +1,20 @@ + +//(Brakes) Example 12.2 +//Total mass of the car m (kg) +m = 1000 +//Moment of inertia of each wheel about its transverse axis I (kg-m2) +I = 0.5 +//Rolling radius of the wheel R (m) +R = 0.35 +//Moment of inertia of other parts of the car Ie (kg-m2) +Ie = 2.5 +//Ratio of speed of engine to the speed of wheels r +r = 5 +//Speed of the car v1 (km/h) +v1 = 100 +//Car deceleration dec (m/s2) +dec = 0.5 * 9.81 +//Final speed of the car v2 (km/h) +v2 = 0 +//Number of wheels n +n = 4 diff --git a/764/CH12/EX12.2.b/result12_2.txt b/764/CH12/EX12.2.b/result12_2.txt new file mode 100755 index 000000000..0fd8cbe6e --- /dev/null +++ b/764/CH12/EX12.2.b/result12_2.txt @@ -0,0 +1,72 @@ +-->//(Brakes) Example 12.2
+
+-->//Total mass of the car m (kg)
+
+-->m = 1000
+ m =
+
+ 1000.
+
+-->//Moment of inertia of each wheel about its transverse axis I (kg-m2)
+
+-->I = 0.5
+ I =
+
+ 0.5
+
+-->//Rolling radius of the wheel R (m)
+
+-->R = 0.35
+ R =
+
+ 0.35
+
+-->//Moment of inertia of other parts of the car Ie (kg-m2)
+
+-->Ie = 2.5
+ Ie =
+
+ 2.5
+
+-->//Ratio of speed of engine to the speed of wheels r
+
+-->r = 5
+ r =
+
+ 5.
+
+-->//Speed of the car v1 (km/h)
+
+-->v1 = 100
+ v1 =
+
+ 100.
+
+-->//Car deceleration dec (m/s2)
+
+-->dec = 0.5 * 9.81
+ dec =
+
+ 4.905
+
+-->//Final speed of the car v2 (km/h)
+
+-->v2 = 0
+ v2 =
+
+ 0.
+
+-->//Number of wheels n
+
+-->n = 4
+ n =
+
+ 4.
+
+
+Energy absorbed by each brake(E) = 147234.819854 J
+
+Torque capacity of each brake(Mt) = 655.167857 N-m
+
+There is an error in the printed answer
+
\ No newline at end of file diff --git a/764/CH12/EX12.2.b/solution12_2.sce b/764/CH12/EX12.2.b/solution12_2.sce new file mode 100755 index 000000000..4a3d4edf6 --- /dev/null +++ b/764/CH12/EX12.2.b/solution12_2.sce @@ -0,0 +1,31 @@ + +//Obtain path of solution file +path = get_absolute_file_path('solution12_2.sce') +//Obtain path of data file +datapath = path + filesep() + 'data12_2.sci' +//Clear all +clc +//Execute the data file +exec(datapath) +//Calculate the KE of the car KEcar (J) +KEcar = 0.5 * m * ((v1*(5/18))^2 - (v2*(5/18))^2) +//Calculate the initial angular velocity of the wheels w1 (rad/s) +w1 = ((v1*(5/18))/R) +//Calculate the final angular velocity of the wheels w2 (rad/s) +w2 = ((v2*(5/18))/R) +//Calculate the KE of the wheels KEwheel (J) +KEwheel = n * 0.5 * I * (w1^2 - w2^2) +//Calculate the KE of other parts KEother (J) +KEother = 0.5 * Ie * ((r * w1)^2 - w2^2) +//Calculate the energy absorbed by each brake E (J) +E = (KEcar + KEwheel + KEother)/n +//Calculate the time required to bring the car to the rest t (sec) +t = ((v1*(5/18)) - (v2*(5/18)))/dec +//Calculate the average velocity during the braking period wavg (rad/s) +wavg = (w1 + w2)/2 +//Calculate the torque capacity of each brake Mt (N-m) +Mt = E/(wavg * t) +//Print results +printf("\nEnergy absorbed by each brake(E) = %f J\n",E) +printf("\nTorque capacity of each brake(Mt) = %f N-m\n",Mt) +printf("\nThere is an error in the printed answer\n") diff --git a/764/CH12/EX12.3.a/data12_3.sci b/764/CH12/EX12.3.a/data12_3.sci new file mode 100755 index 000000000..20a9d8d34 --- /dev/null +++ b/764/CH12/EX12.3.a/data12_3.sci @@ -0,0 +1,16 @@ + +//(Brakes) Example 12.3 +//Mass m (kg) +m = 2500 +//Initial velocity of the mass v1 (m/s) +v1 = 1.5 +//Mass of the drum M (kg) +M = 50 +//Radius of gyration of the drum k (m) +k = 0.7 +//Mass is brought to rest in a distance of h (m) +h = 0.5 +//Radius of the drum R (m) +R = 0.75 +//Final velocity of the mass v2 (m/s) +v2 = 0 diff --git a/764/CH12/EX12.3.b/result12_3.txt b/764/CH12/EX12.3.b/result12_3.txt new file mode 100755 index 000000000..50bbbf19c --- /dev/null +++ b/764/CH12/EX12.3.b/result12_3.txt @@ -0,0 +1,56 @@ +-->//(Brakes) Example 12.3
+
+-->//Mass m (kg)
+
+-->m = 2500
+ m =
+
+ 2500.
+
+-->//Initial velocity of the mass v1 (m/s)
+
+-->v1 = 1.5
+ v1 =
+
+ 1.5
+
+-->//Mass of the drum M (kg)
+
+-->M = 50
+ M =
+
+ 50.
+
+-->//Radius of gyration of the drum k (m)
+
+-->k = 0.7
+ k =
+
+ 0.7
+
+-->//Mass is brought to rest in a distance of h (m)
+
+-->h = 0.5
+ h =
+
+ 0.5
+
+-->//Radius of the drum R (m)
+
+-->R = 0.75
+ R =
+
+ 0.75
+
+-->//Final velocity of the mass v2 (m/s)
+
+-->v2 = 0
+ v2 =
+
+ 0.
+
+
+Energy absorbed by the brakes(E) = 15124.000000 J
+
+Torque capacity of the brakes(Mt) = 22686.000000 N-m
+
\ No newline at end of file diff --git a/764/CH12/EX12.3.b/solution12_3.sce b/764/CH12/EX12.3.b/solution12_3.sce new file mode 100755 index 000000000..eb0ea4c1e --- /dev/null +++ b/764/CH12/EX12.3.b/solution12_3.sce @@ -0,0 +1,28 @@ + +//Obtain path of solution file +path = get_absolute_file_path('solution12_3.sce') +//Obtain path of data file +datapath = path + filesep() + 'data12_3.sci' +//Clear all +clc +//Execute the data file +exec(datapath) +//Calculate the KE of the mass KEmass (J) +KEmass = 0.5 * m * (v1^2 - v2^2) +//Calculate the initial velocity of the drum w1 (rad/s) +w1 = v1/R +//Calculate the final velocity of the drum w2 (rad/s) +w2 = v2/R +//Calculate the KE of the drum KEdrum (J) +KEdrum = 0.5 * M * k^2 * (w1^2 - w2^2) +//Calculate the PE of the mass PEmass (J) +PEmass = m * 9.81 * h +//Calculate the total energy absorbed by the brakes E (J) +E = KEmass + KEdrum + PEmass +//Calculate the angle through which the drum rotates during the braking period theta (rad) +theta = (h/R) +//Calculate the torque capacity of the brake Mt (N-m) +Mt = E/theta +//Print results +printf("\nEnergy absorbed by the brakes(E) = %f J\n",E) +printf("\nTorque capacity of the brakes(Mt) = %f N-m\n",Mt) diff --git a/764/CH12/EX12.4.a/data12_4.sci b/764/CH12/EX12.4.a/data12_4.sci new file mode 100755 index 000000000..ba74a4137 --- /dev/null +++ b/764/CH12/EX12.4.a/data12_4.sci @@ -0,0 +1,22 @@ + +//(Brakes) Example 12.4 +//Torque capacity of the block brake Mt (N-m) +Mt = 250 +//Speed of the brake n (rpm) +n = 100 +//Coefficient of friction mu +mu = 0.35 +//Intensity of pressure between the block and the drum p (N/mm2) +p = 1 +//Ratio of the length of the block to its width r +r = 2 +//Distance of the actuating force from the block d1 (mm) +d1 = 300 +//Distance of the lever pivot from the block d2 (mm) +d2 = 200 +//Distance between the lever pivot from the contact area d3 (mm) +d3 = 50 +//Radius of the drum R (mm) +R = 200 +//Final velocity of the brake drum v2 (m/s) +v2 = 0 diff --git a/764/CH12/EX12.4.b/result12_4.txt b/764/CH12/EX12.4.b/result12_4.txt new file mode 100755 index 000000000..4e63e6150 --- /dev/null +++ b/764/CH12/EX12.4.b/result12_4.txt @@ -0,0 +1,93 @@ +-->//(Brakes) Example 12.4
+
+-->//Torque capacity of the block brake Mt (N-m)
+
+-->Mt = 250
+ Mt =
+
+ 250.
+
+-->//Speed of the brake n (rpm)
+
+-->n = 100
+ n =
+
+ 100.
+
+-->//Coefficient of friction mu
+
+-->mu = 0.35
+ mu =
+
+ 0.35
+
+-->//Intensity of pressure between the block and the drum p (N/mm2)
+
+-->p = 1
+ p =
+
+ 1.
+
+-->//Ratio of the length of the block to its width r
+
+-->r = 2
+ r =
+
+ 2.
+
+-->//Distance of the actuating force from the block d1 (mm)
+
+-->d1 = 300
+ d1 =
+
+ 300.
+
+-->//Distance of the lever pivot from the block d2 (mm)
+
+-->d2 = 200
+ d2 =
+
+ 200.
+
+-->//Distance between the lever pivot from the contact area d3 (mm)
+
+-->d3 = 50
+ d3 =
+
+ 50.
+
+-->//Radius of the drum R (mm)
+
+-->R = 200
+ R =
+
+ 200.
+
+-->//Final velocity of the brake drum v2 (m/s)
+
+-->v2 = 0
+ v2 =
+
+ 0.
+
+
+The brake is not self-locking
+
+FOR CLOCKWISE ROTATION
+
+Actuating force(Pc) = 1303.571429 N
+
+Reaction at the hinge pin(Rc) = 2589.532008 N
+
+FOR ANTICLOCKWISE ROTATION
+
+Actuating force(Pcc) = 1553.571429 N
+
+Reaction at the hinge pin(Rcc) = 2373.656978 N
+
+Rate of heat generated(E) = 1308.996939 W
+
+Width of the block(w) = 42.257713 or 45.000000 mm
+
+Length of the block(l) = 90.000000 mm
+
\ No newline at end of file diff --git a/764/CH12/EX12.4.b/solution12_4.sce b/764/CH12/EX12.4.b/solution12_4.sce new file mode 100755 index 000000000..25b7d4c67 --- /dev/null +++ b/764/CH12/EX12.4.b/solution12_4.sce @@ -0,0 +1,55 @@ +//Function to round-up a value such that it is divisible by 5 +function[v] = round_five(w) + v = ceil(w) + rem = pmodulo(v,5) + if (rem ~= 0) + v = v + (5 - rem) + end +endfunction + +//Obtain path of solution file +path = get_absolute_file_path('solution12_4.sce') +//Obtain path of data file +datapath = path + filesep() + 'data12_4.sci' +//Clear all +clc +//Execute the data file +exec(datapath) +//Calculate the normal reaction of the drum on the lever N (N) +N = (Mt * 1000)/(mu * R) +//For CLOCKWISE ROTATION +//Calculate the actuating force P (N) +Pc = ((N * d2) - (mu * N * d3))/(d1 + d2) +//Calculate the reaction at the pivot R (N) +Rc = sqrt((mu * N)^2 + (N - Pc)^2) +//For ANTICLOCKWISE ROTATION +//Calculate the actuating force P (N) +Pcc = ((N * d2) + (mu * N * d3))/(d1 + d2) +//Calculate the reaction at the pivot R (N) +Rcc = sqrt((mu * N)^2 + (N - Pcc)^2) +//Calculate the initial velocity of the drum v1 (m/s) +v1 = (2 * %pi * n * (R/1000))/60 +//Calculate the average velocity of the drum vavg (m/s) +vavg = (v1 + v2)/2 +//Calculate the rate of heat generated during braking action E (W) +E = mu * N * vavg +//Calculate the width of the block w (mm) +w = sqrt(N/(p * r)) +//Calculate the length of the block l (mm) +l = r * round_five(w) +//Check self-locking tendency +if ((d2/d3) == mu) + printf("\nThe brake is self-locking\n") +else + printf("\nThe brake is not self-locking\n") +end +//Print results +printf("\nFOR CLOCKWISE ROTATION\n") +printf("\nActuating force(Pc) = %f N\n",Pc) +printf("\nReaction at the hinge pin(Rc) = %f N\n",Rc) +printf("\nFOR ANTICLOCKWISE ROTATION\n") +printf("\nActuating force(Pcc) = %f N\n",Pcc) +printf("\nReaction at the hinge pin(Rcc) = %f N\n",Rcc) +printf("\nRate of heat generated(E) = %f W\n",E) +printf("\nWidth of the block(w) = %f or %f mm\n",w,round_five(w)) +printf("\nLength of the block(l) = %f mm\n",l) diff --git a/764/CH12/EX12.5.a/result12_5.sce b/764/CH12/EX12.5.a/result12_5.sce new file mode 100755 index 000000000..3beaf3b81 --- /dev/null +++ b/764/CH12/EX12.5.a/result12_5.sce @@ -0,0 +1,2 @@ +//Example 12.5 from 'Brakes' cannot be coded because almost all the information is obtained from the figure.
+//The entire solution is based on the free-body diagram and not on formulae.
\ No newline at end of file diff --git a/764/CH12/EX12.6.a/data12_6.sci b/764/CH12/EX12.6.a/data12_6.sci new file mode 100755 index 000000000..c07d0209d --- /dev/null +++ b/764/CH12/EX12.6.a/data12_6.sci @@ -0,0 +1,16 @@ + +//(Brakes) Example 12.6 +//Limit of the product pv +pv = 2 +//Coefficient of friction between the drum and the friction lining mu +mu = 0.2 +//Gear ratio between the brake and cable drum g +g = 4 +//Permissible intensity of pressure on friction lining pmax (N/mm2) +pmax = 1 +//Radius of the brake drum Rb (mm) +Rb = 200 +//Radius of the cable drum Rc (mm) +Rc = 150 +//Mass attached to the cable drum m (kg) +m = 500 diff --git a/764/CH12/EX12.6.b/result12_6.txt b/764/CH12/EX12.6.b/result12_6.txt new file mode 100755 index 000000000..7f3ca7639 --- /dev/null +++ b/764/CH12/EX12.6.b/result12_6.txt @@ -0,0 +1,58 @@ +-->//(Brakes) Example 12.6
+
+-->//Limit of the product pv
+
+-->pv = 2
+ pv =
+
+ 2.
+
+-->//Coefficient of friction between the drum and the friction lining mu
+
+-->mu = 0.2
+ mu =
+
+ 0.2
+
+-->//Gear ratio between the brake and cable drum g
+
+-->g = 4
+ g =
+
+ 4.
+
+-->//Permissible intensity of pressure on friction lining pmax (N/mm2)
+
+-->pmax = 1
+ pmax =
+
+ 1.
+
+-->//Radius of the brake drum Rb (mm)
+
+-->Rb = 200
+ Rb =
+
+ 200.
+
+-->//Radius of the cable drum Rc (mm)
+
+-->Rc = 150
+ Rc =
+
+ 150.
+
+-->//Mass attached to the cable drum m (kg)
+
+-->m = 500
+ m =
+
+ 500.
+
+
+Brake shoe force(P) = 4598.437500 N
+
+Area of friction lining(A) = 4598.437500 mm2
+
+Uniform velocity at which the mass can be lowered(v1) = 0.375000 m/s or 22.500000 m/min
+
\ No newline at end of file diff --git a/764/CH12/EX12.6.b/solution12_6.sce b/764/CH12/EX12.6.b/solution12_6.sce new file mode 100755 index 000000000..6411e914e --- /dev/null +++ b/764/CH12/EX12.6.b/solution12_6.sce @@ -0,0 +1,25 @@ + +//Obtain path of solution file +path = get_absolute_file_path('solution12_6.sce') +//Obtain path of data file +datapath = path + filesep() + 'data12_6.sci' +//Clear all +clc +//Execute the data file +exec(datapath) +//Calculate the actuating force P (N) +P = (m * 9.81 * Rc)/(g * mu * Rb) +//Calculate the area of friction lining A (mm2) +A = P/pmax +//Calculate the peripheral velocity of the brake drum v2 (m/s) +v2 = pv/pmax +//Calculate the angular velocity of the brake drum w2 (rad/s) +w2 = v2/Rb +//Calculate the angular velocity of the cable drum w1 (rad/s) +w1 = w2/g +//Calculate the peripheral velocity of the cable drum v1 (m/s) +v1 = w1 * Rc +//Print results +printf("\nBrake shoe force(P) = %f N\n",P) +printf("\nArea of friction lining(A) = %f mm2\n",A) +printf("\nUniform velocity at which the mass can be lowered(v1) = %f m/s or %f m/min\n",v1,v1*60) diff --git a/764/CH12/EX12.7.a/data12_7.sci b/764/CH12/EX12.7.a/data12_7.sci new file mode 100755 index 000000000..b2bdb3939 --- /dev/null +++ b/764/CH12/EX12.7.a/data12_7.sci @@ -0,0 +1,12 @@ + +//(Brakes) Example 12.7 +//Angle subtended by the block at the drum theta (deg) +theta = 100 +//Diameter of the brake drum D (mm) +D = 500 +//Width of the friction lining w (mm) +w = 100 +//Coefficient of friction mu +mu = 0.2 +//Maximum intensity of pressure pmax (N/mm2) +pmax = 0.5 diff --git a/764/CH12/EX12.7.b/result12_7.txt b/764/CH12/EX12.7.b/result12_7.txt new file mode 100755 index 000000000..35a61dff0 --- /dev/null +++ b/764/CH12/EX12.7.b/result12_7.txt @@ -0,0 +1,46 @@ +-->//(Brakes) Example 12.7
+
+-->//Angle subtended by the block at the drum theta (deg)
+
+-->theta = 100
+ theta =
+
+ 100.
+
+-->//Diameter of the brake drum D (mm)
+
+-->D = 500
+ D =
+
+ 500.
+
+-->//Width of the friction lining w (mm)
+
+-->w = 100
+ w =
+
+ 100.
+
+-->//Coefficient of friction mu
+
+-->mu = 0.2
+ mu =
+
+ 0.2
+
+-->//Maximum intensity of pressure pmax (N/mm2)
+
+-->pmax = 0.5
+ pmax =
+
+ 0.5
+
+
+Distance of pivot from axis of the drum(h) = 280.588279 mm
+
+Torque capacity of each shoe(Mt) = 957555.553899 N-mm
+
+Reaction in x-direction(Rx) = 17063.356281 N
+
+Reaction in y-direction(Ry) = 3412.671256 N
+
\ No newline at end of file diff --git a/764/CH12/EX12.7.b/solution12_7.sce b/764/CH12/EX12.7.b/solution12_7.sce new file mode 100755 index 000000000..8c340cd2a --- /dev/null +++ b/764/CH12/EX12.7.b/solution12_7.sce @@ -0,0 +1,21 @@ + +//Obtain path of solution file +path = get_absolute_file_path('solution12_7.sce') +//Obtain path of data file +datapath = path + filesep() + 'data12_7.sci' +//Clear all +clc +//Execute the data file +exec(datapath) +//Calculate the distance of the pivot from the axis of the drum h (mm) +h = (4 * (D/2) * sind(theta/2))/((theta * %pi/180) + sind(theta)) +//Calculate the torque capacity of each shoe Mt (N-mm) +Mt = 2 * mu * (D/2)^2 * w * pmax * sind(theta/2) +//Calculate the reactions at the pivot Rx and Ry (N) +Rx = 0.5 * (D/2) * w * pmax * ((theta * %pi/180) + sind(theta)) +Ry = 0.5 * mu * (D/2) * w * pmax * ((theta * %pi/180) + sind(theta)) +//Print results +printf("\nDistance of pivot from axis of the drum(h) = %f mm\n",h) +printf("\nTorque capacity of each shoe(Mt) = %f N-mm\n",Mt) +printf("\nReaction in x-direction(Rx) = %f N\n",Rx) +printf("\nReaction in y-direction(Ry) = %f N\n",Ry) diff --git a/764/CH12/EX12.8.a/data12_8.sci b/764/CH12/EX12.8.a/data12_8.sci new file mode 100755 index 000000000..4b77be821 --- /dev/null +++ b/764/CH12/EX12.8.a/data12_8.sci @@ -0,0 +1,26 @@ + +//(Brakes) Example 12.8 +//Face width of the friction lining w (mm) +w = 40 +//Maximum intensity of normal pressure pmax (N/mm2) +pmax = 1 +//Coefficient of friction mu +mu = 0.32 +//Radius of the drum R (mm) +R = 125 +//All angles are taken from the same reference +//Angles of the shoe theta1 and theta2 +theta1 = 0 +theta2 = 120 +//Distance of the force from the horizontal centerline d1 (mm) +d1 = 100.9 +//Distance of the pivot from the horizontal centerline d2 (mm) +d2 = 86.6 +//Distance of the pivot from the vertical centerline d3 (mm) +d3 = 50 +//Maximum normal pressure occurs at angle fi (deg) +if (theta2 > 90) + fi = 90 +else + fi = theta2 +end diff --git a/764/CH12/EX12.8.b/result12_8.txt b/764/CH12/EX12.8.b/result12_8.txt new file mode 100755 index 000000000..45480db8b --- /dev/null +++ b/764/CH12/EX12.8.b/result12_8.txt @@ -0,0 +1,81 @@ +-->//(Brakes) Example 12.8
+
+-->//Face width of the friction lining w (mm)
+
+-->w = 40
+ w =
+
+ 40.
+
+-->//Maximum intensity of normal pressure pmax (N/mm2)
+
+-->pmax = 1
+ pmax =
+
+ 1.
+
+-->//Coefficient of friction mu
+
+-->mu = 0.32
+ mu =
+
+ 0.32
+
+-->//Radius of the drum R (mm)
+
+-->R = 125
+ R =
+
+ 125.
+
+-->//All angles are taken from the same reference
+
+-->//Angles of the shoe theta1 and theta2
+
+-->theta1 = 0
+ theta1 =
+
+ 0.
+
+-->theta2 = 120
+ theta2 =
+
+ 120.
+
+-->//Distance of the force from the horizontal centerline d1 (mm)
+
+-->d1 = 100.9
+ d1 =
+
+ 100.9
+
+-->//Distance of the pivot from the horizontal centerline d2 (mm)
+
+-->d2 = 86.6
+ d2 =
+
+ 86.6
+
+-->//Distance of the pivot from the vertical centerline d3 (mm)
+
+-->d3 = 50
+ d3 =
+
+ 50.
+
+-->//Maximum normal pressure occurs at angle fi (deg)
+
+-->if (theta2 > 90)
+--> fi = 90
+ fi =
+
+ 90.
+-->else
+--> fi = theta2
+-->end
+
+
+Actuating force(P) = 2089.795894 N
+
+Torque absorbing capacity of the brake(Mt) = 434831.051530 N-mm
+
\ No newline at end of file diff --git a/764/CH12/EX12.8.b/solution12_8.sce b/764/CH12/EX12.8.b/solution12_8.sce new file mode 100755 index 000000000..ab5e86c78 --- /dev/null +++ b/764/CH12/EX12.8.b/solution12_8.sce @@ -0,0 +1,36 @@ + +//Obtain path of solution file +path = get_absolute_file_path('solution12_8.sce') +//Obtain path of data file +datapath = path + filesep() + 'data12_8.sci' +//Clear all +clc +//Execute the data file +exec(datapath) +//Calculate the distance of the pivot from the axis of the brake drum h (mm) +h= sqrt(d2^2 + d3^2) +//For RIGHT SHOE +//Calculate the moment of the frictional force about the pivot Mf (N-mm) +Mf = mu * pmax * R * w * (4 * R * (cosd(theta1) - cosd(theta2)) - h * (cosd(2 * theta1) - cosd(2 * theta2)))/(4 * sind(fi)) +//Calculate the moment of the normal force about the pivot Mn (N-mm) +Mn = pmax * R * w * h * (2 * (theta2 - theta1) * (%pi/180) - (sind(2 * theta2) - sind(2 * theta1)))/(4 * sind(fi)) +//Calculate the actuating force P (N) +P = (Mn - Mf)/(d1 + d2) +//Calculate the torque absorbing capacity Mtr +Mtr = mu * R^2 * pmax * w * (cosd(theta1) - cosd(theta2))/sind(fi) +//For LEFT SHOE +//Assume the maximum intensity of pressure for LEFT SHOE to be 1 N/mm2 plmax +plmax = 1 +//Calculate the moment of the frictional force about the pivot Mfl (N-mm) +Mlf = Mf * plmax/pmax +//Calculate the moment of the normal force about the pivot Mnl (N-mm) +Mln = Mn * plmax/pmax +//Calculate the actual maximum intensity of pressure plmax (N/mm2) +plmax = P * (d1 + d2)/(Mlf + Mln) +//Calculate the torque absorbing capacity Mtl (N-mm) +Mtl = Mtr * (plmax/pmax) +//Calculate the total torque absorbing capacity of the brake Mt (N-mm) +Mt = Mtr + Mtl +//Print results +printf("\nActuating force(P) = %f N\n",P) +printf("\nTorque absorbing capacity of the brake(Mt) = %f N-mm\n",Mt) diff --git a/764/CH12/EX12.9.a/data12_9.sci b/764/CH12/EX12.9.a/data12_9.sci new file mode 100755 index 000000000..c716f7203 --- /dev/null +++ b/764/CH12/EX12.9.a/data12_9.sci @@ -0,0 +1,26 @@ + +//(Brakes) Example 12.9 +//Face width of the friction lining w (mm) +w = 50 +//Maximum intensity of normal pressure pmax (N/mm2) +pmax = 1 +//Coefficient of friction mu +mu = 0.3 +//Radius of the drum R (mm) +R = 250 +//All angles are taken from the same reference +//Angles of the shoe theta1 and theta2 +theta1 = 15 +theta2 = 75 +//Maximum normal pressure occurs at angle fi (deg) +if (theta2 > 90) + fi = 90 +else + fi = theta2 +end +//Distance of the force from the horizontal centerline d1 (mm) +d1 = 200 +//The distance of the pivot from the axis of the brake drum h (mm) +h= 200 +//Distance of the pivot from the vertical centerline d2 (mm) +d2 = 50 diff --git a/764/CH12/EX12.9.b/result12_9.txt b/764/CH12/EX12.9.b/result12_9.txt new file mode 100755 index 000000000..6cf2d5555 --- /dev/null +++ b/764/CH12/EX12.9.b/result12_9.txt @@ -0,0 +1,81 @@ +-->//(Brakes) Example 12.9
+
+-->//Face width of the friction lining w (mm)
+
+-->w = 50
+ w =
+
+ 50.
+
+-->//Maximum intensity of normal pressure pmax (N/mm2)
+
+-->pmax = 1
+ pmax =
+
+ 1.
+
+-->//Coefficient of friction mu
+
+-->mu = 0.3
+ mu =
+
+ 0.3
+
+-->//Radius of the drum R (mm)
+
+-->R = 250
+ R =
+
+ 250.
+
+-->//All angles are taken from the same reference
+
+-->//Angles of the shoe theta1 and theta2
+
+-->theta1 = 15
+ theta1 =
+
+ 15.
+
+-->theta2 = 75
+ theta2 =
+
+ 75.
+
+-->//Maximum normal pressure occurs at angle fi (deg)
+
+-->if (theta2 > 90)
+--> fi = 90
+-->else
+--> fi = theta2
+ fi =
+
+ 75.
+-->end
+
+-->//Distance of the force from the horizontal centerline d1 (mm)
+
+-->d1 = 200
+ d1 =
+
+ 200.
+
+-->//The distance of the pivot from the axis of the brake drum h (mm)
+
+-->h= 200
+ h =
+
+ 200.
+
+-->//Distance of the pivot from the vertical centerline d2 (mm)
+
+-->d2 = 50
+ d2 =
+
+ 50.
+
+
+Actuating force(P) = 5025.457606 N
+
+Torque absorbing capacity of the brake with 4 shoes(Mt) = 2181614.276244 N-mm
+
\ No newline at end of file diff --git a/764/CH12/EX12.9.b/solution12_9.sce b/764/CH12/EX12.9.b/solution12_9.sce new file mode 100755 index 000000000..f219618a5 --- /dev/null +++ b/764/CH12/EX12.9.b/solution12_9.sce @@ -0,0 +1,34 @@ + +//Obtain path of solution file +path = get_absolute_file_path('solution12_9.sce') +//Obtain path of data file +datapath = path + filesep() + 'data12_9.sci' +//Clear all +clc +//Execute the data file +exec(datapath) +//For RIGHT SHOE +//Calculate the moment of the frictional force about the pivot Mf (N-mm) +Mf = mu * pmax * R * w * (4 * R * (cosd(theta1) - cosd(theta2)) - h * (cosd(2 * theta1) - cosd(2 * theta2)))/(4 * sind(fi)) +//Calculate the moment of the normal force about the pivot Mn (N-mm) +Mn = pmax * R * w * h * (2 * (theta2 - theta1) * (%pi/180) - (sind(2 * theta2) - sind(2 * theta1)))/(4 * sind(fi)) +//Calculate the actuating force P (N) +P = (Mn - Mf)/d1 +//Calculate the torque absorbing capacity Mtr +Mtr = mu * R^2 * pmax * w * (cosd(theta1) - cosd(theta2))/sind(fi) +//For LEFT SHOE +//Assume the maximum intensity of pressure for LEFT SHOE to be 1 N/mm2 plmax +plmax = 1 +//Calculate the moment of the frictional force about the pivot Mfl (N-mm) +Mlf = Mf * plmax/pmax +//Calculate the moment of the normal force about the pivot Mnl (N-mm) +Mln = Mn * plmax/pmax +//Calculate the actual maximum intensity of pressure plmax (N/mm2) +plmax = P * d1/(Mlf + Mln) +//Calculate the torque absorbing capacity Mtl (N-mm) +Mtl = Mtr * (plmax/pmax) +//Calculate the total torque absorbing capacity of the brake Mt (N-mm) +Mt = Mtr + Mtl +//Print results +printf("\nActuating force(P) = %f N\n",P) +printf("\nTorque absorbing capacity of the brake with 4 shoes(Mt) = %f N-mm\n",2*Mt) |