amceuma's blog

Hi dear friends 

I am working about wave propagation modeling in solids. in FEM for 1D beam model when governed differential equation of motion is solving by central difference method the output results of displacement are nondispersive but by using MATLAB "lsim" command for simulation of LTI system for arbitrary inputs, the outputs are dispersive which we expect this phenomenon will be happen in beam like models!

in bar models both methods leads to nondispersive results which is resonable.

could you help me? 

Dear friends

I want to model a beam as a 1D structure using radial point interpolation meshfree method. there are expalnations in the chapter 10 of "meshfree method moving..." by Prof.Liu about PIM for beam modeling and not for RPIM. in PIM modelling we can consider 2*(number of nodes in support domain) terms of polynomials for extraction of moment matrix RQ because of the deflection and rotation dof in each node but it is not applicable for RPIM. what is the solution for overcomming to this problem?  could you help me about the shape function construction for this problem? 

Hello everybody