Computational Mechanics Forum

Hi,

I've been reading the book on Non-Linear Finite Element Analysis by Crisfield and have the following questions:

1.Considring the equation 1.10 in Crisfield's book on page 4, it is:

Kt = EA/l (z/l)^2 + EA/l (2zw + w^2/ L^2) + N/L

where:

Kt->is the tangent stiffness matrix

z->in itial displacement

L->Length of the bar-as an approximation the undeformed length of the bar is considered.

N->internal force in the bar.

 Hi, 

Geometric non-linearity:Incremental solution

1.I've been reading the book by Crisfield on Non Linear finite element analysis and have just started with the first chapter wherein the author introduces geometric non-linearity.

I have some questions on the incremental (Euler) approach here:

I want to know whether my inetrpretations below are correct:

1)The incremental approach makes use of the tangent stiffness which relates small changes in load to small changes in displacement.

2)The "LOAD" is incremented in steps.

I would like to make a career in Finite Element MEthod with concentration on topics like XFEM,Mesh-free methods--

However, I am yet to mmake a start.To give you my background I ahve a good knowledge of subject of Strength of Materials,Linear Finite Element Analyis-including coding structrial analysis involving beam elements,plate elements,plane stress and plane strain elements-all linear FE.

I have good programming skills-C,VB,MathCAD and know basis of C++ well

I havee just undergone a course on Linear Algebra through the MIT opencourseware.

I am trying to model a rubber impregnated fabric as rebar in Abaqus Standard. It seems that the rebar is only good in uniaxial tension load and it causes convergence problem in bending and compression loading. The fabric and rubber matrix has a compressive strength and that is critical to the model that I am analyzing. What would be a good approach to include compression on fabric rebar? The compressive strength of fabric matrix should be an order of magnitude lower than the tensile strength but I do not have a test data in compressive loading.

Hi,

I am trying to develop a finite element code to capture the residual stresses during the cooling of a viscoelastic body.

Can anyone suggest references or papers that address the finite element formulation of a thermoviscoelastic problem? I have found a couple of papers, but they do not seem to directly apply to what I want.

Thanks, 

Shriram

Research Assistant

University of Florida

Hi All, thanks in advance for any replies.

I am currently doing my Thesis on fast stress analysis using the boundary element method and specifically, adaptive cross approximation. I ofter come across the terms "single layer potential" and "double layer potential", i "know" what they are mathematically, i was wondering if anyone could give me an insight into what they mean physically, or just give a simple non mathematical definition? Thanks a lot, Ian.