Contact-based Thermal Analysis

In OptiStruct, structural models involving contact are solved by using Small Displacement Nonlinear Analysis.

The analysis involves finding the contact status, such as contact clearance and pressure. Contact clearance spans the distance between the master and slave, while contact pressure is developed between two surfaces in contact.

Thermal Contact Analysis via PCONTHT and PGAPHT is supported for Linear Steady-State Heat Transfer, Linear Transient Heat Transfer, Nonlinear Steady-State Heat Transfer, and Nonlinear Transient Heat Transfer analyses. Thermal Contact is also supported for One-Step Thermal Transient Stress Analysis (OSTTS).

The traditional thermal structural analysis is one-way coupling, in the sense that thermal analysis influences structural analysis by providing temperature, but structural problem does not affect the thermal problem.

Figure 1. Thermal Results Affects the Structural Problem

When contact problems are involved, thermal structural analysis becomes fully coupled since contact status changes thermal conductance.

Figure 2. Contact Status Affects the Thermal Problem

In Figure 1, you can see that a change in contact status does not affect the thermal problem. This may lead to inaccurate solutions if thermal conductance depends on the contact status. In Figure 2, the contact clearance and/or pressure changes during the course of the quasi-static nonlinear analysis, the corresponding change in the thermal conductance will affect the solution of the thermal problem.