VELOCITY AND ACCELERATION OF CONNECTING ROD CRANK MECHANISM IN PYTHON

Before you start coding i highly recommend watch this video to understand how this code work

import matplotlib.pyplot as plt

from numpy import *

from ipywidgets import interactive

def f(theta,c,cR): # creating a function that give angle to crank c = crank radius  cR = connecting rod length

    g = plt.figure(figsize=(20,20))

    ax = g.add_subplot(311)

    ax2 = g.add_subplot(312)

    ax3 = g.add_subplot(313)

    omega =20 # crank speed in radians per second

    xa= 0 # starting point of x cordinate of crank

    ya = 0 # starting point of y cordinate of crank

    xb = c*cos(radians(theta)) # ending/starting point of x cordinate of crank/connecting rod

    yb = c*sin(radians(theta))  # ending/starting point of y cordinate of crank/connecting rod

    xc = xb + sqrt(cR**2-yb**2) # ending x cordinate of connecting rod

    

    yc =0 # ending y cordinate of connecting rod

    ax = g.add_subplot(311)

    x =([xa,xb,xc]) 

    y =([ya,yb,yc])

    plt.xlabel ('distance in meter')

    plt.ylabel('distance')

    plt.title('connecting rod mechanism in python')

    ax.plot(x,y)

    print('distance of piston from crankshaft is ',xc)

    #plt.axis('equal') #make length  x and y coordinate equal

    

    ##VELCOITY GRAPH PLOTTING 

    

    ax2 = g.add_subplot(312)

    

    t = linspace(0,theta,360)

 

    n = cR/c

    velocity = omega*c*(sin(radians(t))+(sin(2*radians(t)))/(2*n)) # formula from page 524 rs khurmi theory of machine

    ax2.plot(t,velocity)

    plt.title('Velocity graph')

    plt.xlabel('theta')

    plt.ylabel('velocity')

    #plt.axis('equal')

    #print("velocity of crank at ",theta," is ", velocity)

    

    

    ##ACCELERATION GRAPH PLOTTING 

    ax3 = g.add_subplot(313)

    t = linspace(0,theta,360)

    n = cR/c            # ratio of connecting rod length / crank radius

    acceleration = omega**2*c*(cos(radians(t))+(cos(2*radians(t)))/(n)) # formula from page 525 rs khurmi theory of machine

    ax3.plot(t,acceleration)

    plt.title('Acceleration graph')

    plt.xlabel('theta')

    plt.ylabel('acceleration')

    #plt.axis('equal')

    #print("acceleration of crank at ",theta," is ", acceleration)

    

    

    #print('velocity at particular angle is ',velocity)

interactive_plot = interactive(f,theta=(0,360),c = (0,0.7),cR = (0.5,1))

interactive_plot

for better understanding of code watch this video