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辅导案例-MEC4428

By May 15, 2020留学咨询

MONASH UNIVERSITYDepartment of Mechanical and Aerospace EngineeringMEC4428 — Advanced Dynamics —Assignment 2: Rigid Body Dynamics — The Motion of a Com-pound Pendulum due: Thursday 10am – 17th October 2018, assignment box building31A correct worked derivation of the governing equations with accompanying extracts of the functionfile, and the commands to solve for and plot the solutions will earn 4 marks contributing to yourfinal score.A Compound PendulumWrite a MATLAB code to determine the motion of the two component pendulum shown in thefigure below. The two parts are both rigid bodies, connected by a pivot at point D. The first linkis pinned at the point O. Specifically:1. plot the trajectory of point C, the centre of the square,2. plot the phase portraits (θ˙ versus θ and φ˙ versus φ),3. plot the total energy – this should be a constant as there is no dissipation,4. finally, determine the approximate governing equations for small angles (i.e.,θ → 0, φ → pi). Compare the solution from the original set of equations with theapproximate set for initial conditions θ(0) = pi/12, φ(0) = pi − pi/12, θ˙(0) = φ˙(0) = 0.You have choice of how to derive the equations. You can use Angular Momentum Balancefor the disk about the point D and for the whole system about O. You could also substitute oneof these equations with total energy conservation for the two masses. It is also possible to useeither virtual work or the Lagrange equations. In any case you should get a system of 4 first-orderdifferential equations for θ˙, θ¨, φ˙, φ¨, which will then be solved using your favourite MATLAB ODEsolver (typically ODE45). Assume the following parameters and initial conditions. I have putup some MATLAB code for a double pendulum (two rods) that you might like to modify for thecurrent problem.• m1 = m2 = m = 1• L = 2, H = 1 (IS = mH2/6; IR = mL2/12)• d = 1/6 (the length CD)• g = 1 (Note this is not a mistake – the problem has been non-dimensionalised…)• θ(0) = pi/2, φ(0) = pi/2• θ˙(0) = φ˙(0) = 01HRm, R, ISOCGθφDm, L, I2

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