MAT162 is a rate dependent progressive composite damage model for solid elements. In composite shell elements, transverse shear damage cannot be defined and this is why a composite solid element defining transverse shear damage is essential in modeling problems where transverse shear damage is important. Shell elements are efficient for thin-section composites, whereas thick-section composites can be modeled using multiple through-thickness elements. MAT162 for solid elements have unique quadratic progressive damage modes, which no other material model offers. These unique damage modes, such as, (i) Tension-Shear, (ii) Axial Compression, (iii) Inter laminar Shear (ILS) and Delamination, (iv) Fiber Shear (FS) or Punch Shear (PS), and (v) Fiber Crush provides the theoretical framework for modeling most known composite damages.

Benefits of MAT162 progressive damage can be elucidated with simple examples. Consider the transverse impact of a 20mm sphere with an impact velocity of 50 m/s on an 80mm x 80mm x 2mm composite plate modeled with perfectly clamped boundary condition. Shell elements with MAT054 and solid elements with MAT162 damage predictions shows that MAT054 can only model in-plane tension and compression damage, while MAT162 can predict tension-shear along direction 1 & 2, in-plane shear, transverse shear and associated delamination.

In modeling out-of-plane deformation of any kind, the primary damage mode is tension-shear where MAT162 defines a quadratic damage function with in-plane tension and out-of-plane shear properties for the initiation of tension-shear damage.

The MAT054 equivalent damage function uses in-plane tension and in-plane shear properties instead, and in general fails to account for transverse shear deformation.

The inability of MAT54 in modeling transverse damage modes greatly affects the impact-contact force and associated work done, predicts premature perforation while MAT162 predicts partial perforation and complete rebound of the sphere in case of initial impact velocity of 50 m/s.

Quantitative Comparison between MAT054 (Shell) & MAT162 (Solid) Material Models

A local MAT162 solid model in the anticipated damage region combined with global shell elements can be used to efficiently and accurately model large-scale impact application such as, crash analysis of automotive composite components and aerospace structures under impact conditions.

This example problem can be downloaded here.

EXAMPLE 2: Sphere-Impact-on-Composites-SHELL-MAT54.zip This zip folder contains the following KEWORD files. Run the first file. 001-Sphere-Impact-on-Composite-Shell.key 002-control-cards.key 003-Shell-Plate-80mm-x-80-mm-FEM.key 004-700-Sphere-FEM.key 005-parts-partsets-sections-materials-FEM.key 006-100-Node-SET.key 006-nodeset-elementset-segmentset-FEM.key 007-contact-single-surface.key 008-boundary-conditions.key 009-initial-conditions.key 010-loading-conditions.key 011-output-database.key

In the above file lists, the file 001- is the input file, which includes all other files.