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Mario Juha's blog

selection methodology of femoral stems according to the cross section and the maximum stress

Submitted by Mario Juha on

In the following doi, I share with the community our new tech brief ("selection methodology of femoral stems according to the cross section and the maximum stress") about design of femoral stems, published in the journal of biomechanical engineering of ASME.

doi: https://doi.org/10.1115/1.4053006

 

LES and RANS simulation of wind- and wave-forced oceanic turbulent boundary layers in shallow water with wall modeling

Submitted by Mario Juha on

Large-eddy simulation (LES) and Reynolds-averaged Navier-Stokes (RANS) simulation of wind and wave forced oceanic turbulence in unstratified shallow water are performed in order to investigate the influence of wall modeling on results. The LES is also used to investigate the dependence of results on downwind and crosswind lengths of the computational domain, representative of a shallow shelf coastal ocean (10-to-30 m deep) unaffected by lateral boundaries.

Large-eddy simulation with near-wall modeling using weakly enforced no-slip boundary conditions

Submitted by Mario Juha on

In the present paper, weakly enforced no-slip wall boundary conditions are revisited in the context of Large-Eddy Simulations (LES) with near-wall modeling. A new formulation is proposed in the framework of weakly enforced no-slip conditions that is better aligned with traditional near-wall modeling approaches than its predecessors. The new formulation is tested on turbulent open-channel flows at friction-velocity-based Reynolds numbers Reτ=395Reτ=395 and 950 benchmark problems.

Symmetric global partition polynomials for reproducing kernel elements

Submitted by Mario Juha on

The reproducing kernel element method is a numerical technique that combines finite element and meshless methods to construct shape functions of arbitrary order and continuity, yet retains the Kronecker-δ property. Central to constructing these shape functions is the construction of global partition polynomials on an element. This paper shows that asymmetric interpolations may arise due to such things as changes in the local to global node numbering and that may adversely affect the interpolation capability of the method.

Is peridynamics a superset of Continuum Mechanics?

Submitted by Mario Juha on

Recently, I have found a new theory, called Peridynamics, used to solve, mainly, fracture mechanics problems in materials. But, I am confused about the issue if it is a superset of continuum mechanics or is it a totally new theory that reformulate our previous understanding of continuum mechanics? How do you measure material properties with this theory? Do we need to reformulate our theories to deal with fracture mechanics problems? Is it a totally accepted scientific theory?

 

cordially,

 

Mario J. Juha

Consistent linearized tangent moduli for hyperelastic materials... is it always a positive definite matrix?

Submitted by Mario Juha on

In order to obtain numerical solution of problemsthat involves a hyperelastic material model, we use what is known as incremental/iterative solution techniques of Newthon's type. The basic idea is to contruct a discrete system of nonlinear equation, KU=F, and solving it using a Newton's method or a modified version of it. As we know, its lead to a systematic linearization of the internal force vector and by the chain rule to the linearization of the material model.

Why ANSYS not ABAQUS?

Submitted by Mario Juha on

I would like to know why ABAQUS is the dominant FEM program (in terms of comments) in this forum? Why do you consider ABAQUS over ANSYS?

I have been using ANSYS for at least 8 years and I am very please with the capabilities of it. But I have not seen ABAQUS or used it. Beside, reading all the comments that are posted in imechanica, I feel like I am using the wrong FEM program. 

Which are the advantage of ABAQUS over ANSYS?

 

Thank you,

 Mario J . Juha