# mjalilych1's blog

## 2D corotational beam

hello Dear friends

I am phd student in mechanical engineering. I want to compare field consistent total lagrangian

and corotational formulation for geometrically nonlinear 2D beam analysis. I wrote

a code for total lagrangian approach and my results are exct but in corotational

I have some difficulties in coding. if someone has a sample corotational code please

contact with me.

## ill condition tangent stiffness matrix

hello Dear friends

I study large displacement analysis of euler-bernoulli beam. the beam is under pure bending moment.

wtangent stiffness matrix is dependent to tanget of rotation. so when rotation of nodes approches 90 this matrix become ill condition. I use of matlab for coding. I was wondering if some one give me a solution.

best wishes.

## positional finite element

hello Dear friends

positional fem is introduced by H.B. Coda for studing geometrically nonlinear analysis of 2D beam. I need some information about implementing of this formulation.is there anaone who can help me.

best regards.

## corotational concept

hello Dear friends

I have one question about corotational concept. is it possible to obtain tangent

stiffness matrix by TL approach and updating degrees of freedom(including displacement and

rotation by corotational. please aware me of related papers.

## how to convert total lagrangian tangent stiffness to corotational

hello Dear friends

I am working on large displacement of euler beam. I used total lagrangian approach. because of field consistency between degrees of freedom(displacement and theta) tangent stiffness matrix depends on tangant theta and consequently becomes singular for theta=90. so I am seeking for a method to overcome this problem. I believe that the solution is to remove rigid body rotation from analysis. please correct me. is this reasonable. if yes how should I remove rigid bodu rotation

best regards.

## feasibilty of corotational formulation

hello Dear friends

I am working on geometrically nonlinear behavior of 2D beam.

I used field consistent approach using total lagrangian. because of field consistency, satisfication tangent stiffness matrix is dependent to tangant of node angles. this means that when beam is subjected to pure bending when angle of rotation approches to 90 degree, tangent stiffness matrice become singular. can any one give solution to this problem. how about corotational formulation.

thanks a lot.

best regards.

## cantilever with end moment

hello Dear friends

I am working on large deflection of cantilevers with total lagrangian approach. my code is converged very well in cantilever with end point load but when I apply end moment the problem does not converged and tangent stiffness matrix became singular. if there is any special note that I ignored. please help me.

## large deformation analysis of pinned fixed diamond frame

hello Dear friends

## convert load control to displacement control

Hello Dr. scientists

I want to study nonlinear behavior of williams toggle frame by finite element method.

I use of load control method and my results is a little different. is it reasonable that I change to displacement control. if ok please help me on useful literature in this topic.

## Large deflection of a cantilever

Hi

I am working on large deflection analysis of a cantilever by finite element total lagrangian approach. the results for six element are reasonable but when I increase elemenets to nine solution is diverged. i.e. tangent stiffness matrix becomes singular. can anaone help me on this problem.

## large deformation of cantilever

hello Dear friend

## large deformation of beam element

hello

my name is mohamad. I am phd student in mechanical engineering. I want to use of total lagrangian formulation for analysis of a cantilever. my difficulty is on implementation of newton raphson method and incrementing load. my code does not converge. can you help me. if there is a simple code I was wondering if someone aware me.