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Optimize release angle of a trebuchet (highschool project)?

Posted 6 years ago

Hi, i'm new to using Mathematica and i'm trying to optimize the release angle of a trebuchet using Lagrangian multipliers. I have read much about it and I have come to understand how it is calculated. I ended up going with mathematica to solve the calculations since it is quite a task by hand. I've got a trebuchet with a counterweight pendulum, and a projectile on the end of a sling: enter image description here

i am basing my calculations on the following info and equations https://classes.engineering.wustl.edu/2009/fall/ese251/presentations/(AAM_13)Trebuchet.pdf

I have attached my attempt in solving this using Mathematica. I have tested the method using a much simpler example with success(also attached). What I think is going wrong for me is the notation of the angular velocity and how i represent time.

I would like to find the angle(phi) and time where velocity(kinetic energy) of the projectile is the greatest with a potential energy constraint of 100.

My approach was to use L(the,phi,t)=f(the,phi)??2(g1(the,phi)?c1)-?2(g2(the,phi)?c2)

L(the,phi,t)=0

finding the gradient of 0=f(the,phi)??1(g1(the,phi)?c1)-?2(g2(the,phi)?c2)

f(the,phi)=kinetic energy being optimized, g1(the,phi)=potential energy, c1=100, g2(the,phi)=contreint for sling, c1=0

Thanks in advance

POSTED BY: lasse thiellesen
3 Replies
Posted 6 years ago

All I have on this is in the details of these demonstration.

POSTED BY: Erik Mahieu
Posted 6 years ago

Maybe two of my Wolfram Demonstrations can help?

"Trebuchet Baliistics"

"Optimizing the Counterweight Trebuchet"

POSTED BY: Erik Mahieu

thanks for the reply and links. would you by any chance have en example of the calculations for solving using ND solve that i can have a look at? or a more in depth discription? in the second link do you put the kineic and potential energy equations into L(x,y,…,?)=f(x,y,…)??(g(x,y,…)?c) and simplify? then find the gradiant? would the next step just be placing the constants into the three equations and solving the simultaneous equation for a t value?

POSTED BY: lasse thiellesen
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