multiple equations and boundary values in prime 1...

[ptc-4889506]

hello all,

i have a problem in design course, about shafts.

i have one shaft, that is split to 3 parts by forces.

to find y'', i need to do some differential equations about Mz/EI.

so i have a moments equation for Mz1(x), and another one for Mz2(x).

hence:

y1''=Mz1/EI ; y2''/Mz2/EI

i know that y1(0)=0, and y2(2a)=0, and my third boundary value is about the angle, y1'(a)=y2'(a)

how can i use mathcad prime 1 to solve this ODE problem and find the deflection equations? thanks!

[RogerYeh]

Sure, you can solve this, but maybe not in Prime 1. The way I envision it, use the symbolic solver (available in Prime 2) to integrate twice. You may have to keep track of any constants. Then use the solve block to solve for the constants using the boundary conditions as the constraints.

[RichardJ]

The symbolic solver can't deal with systems of ODEs. There have been some worksheets posted that use Laplace transforms to solve specific problems, but they are the exceptions, not the rule. I don't recall whether or not Prime 1.0 can solve systems of ODE's numerically.

[ValeryOchkov]

May be solutions in this group http://communities.ptc.com/groups/dynamic-models-in-mathcad

help you