Friday, January 8, 2010
Friday, January 23, 2009
This example demonstrates the use of the single-surface contact capability available for two-dimensional large-sliding analysis. Components that deform and change their shape substantially can fold and have different parts of the surface come into contact with each other. In such cases it can be difficult to predict at the outset of the analysis where such contact may occur and, therefore, it can be difficult to define two independent surfaces to make up a contact pair.
This model is used to analyze an oil pan gasket, which enhances the sealing of the oil pan against the engine block. The primary objective is to reach or exceed a threshold value of contact pressure where oil will not leak at the gasket bead/cover/engine block interfaces.
Components that deform and change their shape substantially can fold and have different parts of the surface come into contact with each other. In such cases it can be difficult to predict at the outset of the analysis where such contact may occur and, therefore, it can be difficult to define two independent surfaces to make up a contact pair.
A jounce bumper, sometimes referred to as a “helper spring,” is a highly compressible component that is used as part of the shock isolation system in a vehicle. It is typically located above the coil spring that connects the wheels to the frame. Microcellular material is used because of its high compressibility and low Poisson's ratio value at all but fully compressed configurations.
The bumper initially sits against a fixed flat rigid surface on one end; on the other end, another flat rigid surface is used to model the compression of the bumper. The geometry of the bumper is such that it folds in three different locations. Separate surfaces are defined at the locations where self-contact is expected. This modeling technique produces an economical analysis because the scope of contact searches is limited.
Seals are common structural components that often require design analyses. In this example, a nonlinear finite element analysis of seals is performed. Pressure penetration effects between the seal and the contacting surfaces are to be considered in these analyses, to make routine analyses of seals more realistic and accurate. Analyses of clutch seals, threaded connectors, car door seals and air duct kiss seals are some applications where pressure penetration effects are important. The surface-based pressure penetration capability is used to simulate pressure penetration between contacting surfaces.
This example demonstrates how to model nonlinear material behavior in a composite laminate. The material model in this example includes damage, resulting in nonlinear behavior. It also includes various modes of failure, resulting in abrupt loss of stress carrying capacity.