LS-DYNA is a general purpose finite element code for analyzing the large deformation dynamic response of structures including structures coupled to fluids. The main solution methodology is based on explicit time integration. An implicit solver is currently available with somewhat limited capabilities including structural analysis and heat transfer. A contact-impact algorithm allows difficult contact problems to be easily treated with heat transfer included across the contact interfaces. By a specialization of this algorithm, such interfaces can be rigidly tied to admit variable zoning without the need of mesh transition regions. Other specializations, allow drawbeads in metal stamping applications to be easily modeled simply by defining a line of nodes along the drawbead. Spatial discretization is achieved by the use of four node tetrahedron and eight node solid elements, two node beam elements, three and four node shell elements, eight node solid shell elements, truss elements, membrane elements, discrete elements, and rigid bodies. A variety of element formulations are available for each element type. Specialized capabilities for airbags, sensors, and seatbelts have tailored LS-DYNA for applications in the automotive industry. Adaptive remeshing is available for shell elements and is widely used in sheet metal stamping applications. LS-DYNA currently contains approximately one-hundred constitutive models and ten equations-of-state to cover a wide range of material behavior. LS-DYNA is operational on a large number of mainframes, workstations, MPP's, and PC's.

This theoretical manual has been written to provide users and potential users with insight into the mathematical and physical basis of the code.