Biaxial Testing

Purpose:

Bi-axial testing is used to evaluate the mechanical properties of anisotropic materials (different properties in different directions) that are subjected to multidirectional operational loads. One of the primary applications of biaxial testing is to determine parameters for constitutive models of the material and subsequent computational analysis.

Applications:

Biological and tissue-engineered soft biomaterials are used for many surgical and medical device applications. Software models are being developed to predict soft tissue properties from clinical imaging.  In these applications, constitutive models are important for characterizing the mechanical behaviour of the tissues.  Examples of tissues include myocardium, pericardium used for heart valves, blood vessels, and natural and prosthetic skin.  These tissues are all anisotropic, and a planar biaxial test method is desirable for obtaining model parameters, as well as for determining parameters to differentiate between the properties of different material samples.

Some industrial materials, such as certain textiles,  are designed to function under multidirectional loads. The benefits of biaxial testing for biomaterials equally applies to these industrial materials.

Equipment:

Zymetrix has a Bose Electroforce Planar Biaxial Test Bench. The Test Bench consists of four linear motors mounted on a baseplate with two load cells, one for each direction of loading.  Operating specifications are as follows:

Case Study:

For an illustration of the usage of the planar biaxial system, click here.