Composite Material Properties


Composite materials properties are used only for the thin and thick composite elements. In order to properly enter the properties, the material axes must be defined in the "Element Definition" dialog. (See the pages "Thick Composite Elements" and "Thin Composite Elements".)

 

The composite material properties are listed below. Depending on the element type, analysis type and loads, not all of the material properties may be required. In addition to these properties, it may be necessary to define some isotropic material properties.

 

Symbols used throughout this section are defined as follows:

Ef

modulus of elasticity of the fiber material

Em

modulus of elasticity of the matrix material

Gf

shear modulus of elasticity of the fiber material

Gm

shear modulus of elasticity of the matrix material

mf

Poisson's ratio of the fiber material

mm

Poisson's ratio of the matrix material

Vf

fraction of total volume taken up by the fiber material

Vm

fraction of total volume taken up by the matrix material (=1-Vf)

 

Elastic Properties

Allowable Stresses

The allowable stresses are required if a Tsai-Wu or Maximum Stress failure criteria is specified. Refer to the pages "Thick Composite Elements" and "Thin Composite Elements" for the selection of the failure criteria and the equations that govern failure.

Allowable Strains

The allowable strains are required if the maximum strain failure criteria is specified. Refer to the pages "Thick Composite Elements" and "Thin Composite Elements" for the selection of the failure criteria and the equations that govern failure.

Flexure Controls

By default, the flexural properties will be calculated from the elastic properties. If you want to use specific values for the flexural properties, activate the "Flexural Modulus" checkbox, and then enter the following properties.