Blog posts

Hi everyone 

I am learning the polycrystalline crystal plasticity and testing material in ABAQUS and UMAT. Now I am trying to build a RVE by using the truncated octahedrons as the grain shape or Voronoi tessellations.

For truncated octahedrons, I built a truncated octahedrons and assembled them into the grain aggregate in the .inp file, and assign orientations in the UMAT based on the part's name. However, I found it hard to define their interaction between grains. What is their interaction properties and how to define the contact pair in an automatic way?

The ability to accurately measure mechanical properties, using Nanoindentation, in the fields of Life Science has recently become an important aspect of many current studies. In some cases, understanding the mechanical properties of soft biological surfaces have helped uncover the mechanical effects of diseases. Understanding mechanical properties provides a context for identifying the local mechanical behavior linked to specific changes. It is also critical in the development of artificial bio-materials.

This treatise provides a broad overview of the definitions of
fundamental quantities and methods of analysis for the use of solid materials
in structural components. The presentation is limited to the linear elastic
range of material behavior where there is a one to one relationship between
load and displacement.  Fundamental
methods of analysis and typical results for structures made of elastic solid materials
subjected to axial, bending, torsion, thermal, and internal pressure loading;

 Nature Publishing Index - 2012 Global Top 200

Hi friends,

 Does anybody know what this error mean?

The general contact definition is empty. The definition must include at least one surface. If *CONTACT EXCLUSIONS was defined, check whether the *CONTACT EXCLUSIONS option was specified correctly. Additionally, check whether PURE MASTER-SLAVE formulation is applied to any self-contact situations.

http://jap.aip.org/resource/1/japiau/v113/i19/p193501_s1 

The paper presents a thermodynamically consistent modeling of the non-linear multiphysics of ionic polymer gels based on the multiplicative decomposition of the deformation gradient. In particular, the deformations induced by the motion of ions under an applied voltage are viewed as distortions, similarly to growth-induced deformations in soft tissues. Furthermore, a consistent linearization of the model in the regime of small deformations is discussed. Finally, a finite element implementation of the theory is introduced and validated against experimental results.

I am finding difficulties to obatain the mode shape from Frequency Response Function (FRF). Let know me the brief procedure in the modal analysis.