In this approach, an artificial time parameter is introduced. The final method is suitable for calculations according to the large deformation analysis and for solving problems regarding the post-critical issues. This method is useful for solving post-critical issues where there is a range of instability to overcome. Newton-Raphson with Postcritical Analysis.After a few iterations, a switch is made to the Newton-Raphson method. The approach according to Picard is applied first. The difference between the current and the original iteration run in the current load increment step is considered. The method according to Picard, also known as secant method, can be understood as a finite-difference approximation of the Newton-Raphson method.

The nonlinear equation system is solved numerically by means of iterative approximations with tangents. The approach according to Newton-Raphson is preset for the large deformation analysis. After each iteration step, the stiffness matrix of a deformed system is created.ĭepending on the analysis type, there are various methods available to solve the nonlinear algebraic system of equations. The large deformation analysis (third-order or theory of large deformations) considers longitudinal and transversal forces in the calculation.

In the 'structural' second-order analysis, the equilibrium is determined on a deformed structural system. You can right-click on an object to open a context menu. When calculating according to the geometrically linear analysis (first-order), the equilibrium is analysed on an undeformed structural system. For example, an analysis environment object, such as Static Structural, will eventually contain loads. Settings for an Inertia Relief model will be described in the following example. Note the need for just enough constraint to prevent rigid body motion, and for mass in the model. In RFEM 6, three standard analysis types are preset: Symmetry models are not valid for inertia relief analysis.

Static structural analysis examples