research

Dear all,

 can we say that initial tangent modulus and secant modulus can be considered as upper bound and lower bound limits for uniaxial compressive stress strain curve of concrete?

If so can u show me the literature proof for that?

Thanks

S Rajthilak

hello, I am new to the forum, Hi to all

For the last couple of months I have been struggeling with modeling and coupling of 1D elements with 3Delements of a tube plate, 1D elements are chosen because of obvious reasons, we would like to reduces the mesh.

Dear sir,



I am modeling ligament structures in the knee joint finite element model
with non-linear springs and I am successfully getting non-linear
displacement curve.



My only problem is with the calculation of tension in the springs. I
have a set of non-linear springs representing a particular ligament in
the joint, which is having an elongation when I apply the forces on the
joint. I am giving pre-load to the springs so that they do not have any
slack in them before the analysis. I am also specifying the stiffness of

The Solution of a Differential Equation or a Set of Differential Equations Converges vers the Exact if it is Consistant and it is Stable : Lax's Theorem. Since the Exact is not always known it is convenient to apply this Theorem. Numerical instabilities are a result of Roundoff errors and Truncation errors. The Domain of Stability can be obtained from a Von Newman analysis in the Complex domain. This implies a condition (relation) between the variation steps. 

Mohammed Lamine 

In this contribution (see http://arxiv.org/abs/1306.4385), we derive lower and upper bounds for Wachspress coordinates over any simple d-dimensional simple convex polytope.  Numerical results for the Poisson equation on nontrivial polyhedral meshes are presented that affirm the linear rate of convergence in the energy seminorm of the polyhedral finite element method.  Matlab code to compute the Wachspress shape functions and its gradient on convex polygonal and polyhedral elements is also provided.