In static analysis, there is no mass effect (inertia) or damping. In the dynamic analysis, nodal forces associated with mass/inertia and damping are included. Static analysis is performed using an implicit solver in LS-DYNA. Dynamic analysis can be performed via the explicit solver or the implicit solver. In nonlinear implicit analysis, the solution to each step requires a series of trial solutions (iterations) to establish equilibrium within a certain tolerance. In explicit analysis, no iteration is required because the nodal accelerations are solved directly. The time step in the explicit analysis must be less than the Current time step (time required for a sound wave to pass through an element). Implicit transient analysis has no inherent limit on time step size. Say no to plagiarism. Get a tailor-made essay on “Why Violent Video Games Should Not Be Banned”? Get an original essay As such, implicit time steps are typically several orders of magnitude larger than explicit time steps. Implicit analysis requires a numerical solver to invert the stiffness matrix one or even several times during a load/time step. This matrix inversion is a costly operation, especially for large models. Explicit does not require this step. Explicit analysis handles nonlinearities with relative ease compared to implicit analysis. This would include treatment of contact and material nonlinearities. In explicit dynamic analysis, nodal accelerations are solved directly (and not iteratively) as the inverse of the diagonal mass matrix times the net nodal force vector, where the net nodal force includes contributions from external sources (body forces, applied pressure, contact, etc.), element stress, damping, overall viscosity and hourglass control. Once the accelerations are known at time n, the speeds are calculated at time n+1/2 and the displacements at time n+1. Displacements give rise to tensions. From tension comes stress and the cycle repeats itself (LS-Dyna Support.com, nd). (Hua Song et.al), (Jian Yang et.al) examined the differences between the application of FEA methods by implicit-explicit and explicit-explicit techniques. The Explicit-Explicit method was reported to have the same level of accuracy as the common Implicit-Explicit method. Keep in mind: this is just an example. Get a personalized article from our expert writers now. Get a personalized test The Explicit-Explicit method, however, had a faster and more efficient solver than that of the Implicit-Explicit FEA method. Other researchers tried analytical methods (Mehmet Ali Arslan, 2011) and showed that analytical methods describing the physics of the rail-wheel contact phenomenon were only defined for certain types of simple contact geometries. For complex geometries, analytical models using closed formulations have been stated to remain elusive. (Mehmet Ali Arslan, 2011) performed a static FEA analysis using Ansys on a railway track section and wheel profile to assess stresses..