Why couple HyperSizer with FEA?

[HyperSizer Moderator]

In order to automate the analysis and optimization of real world structures, such as an aerospace vehicle, it is necessary to use a Finite Element Analysis (FEA) package for computation of internal load distributions in the structure. In the aerospace industry, these internal loads are also referred to as 'running-loads' or 'load paths.' In essence, the integrated effects of flight surface pressures, temperatures, and accelerated inertia are reduced to force and moment components on panels and beams for all vehicle locations.

Given that FEA is necessary, the question becomes: What is the best way to determine if finite element predicted panel and beam forces and moments are causing failure? Many different types of failure may occur within a structure. Some of these failures can be predicted using additional FEA package features, some can be accomplished only with very discrete and finely detailed meshes (such as local buckling of stiffened panel spans). Some failure modes cannot be effectively predicted with FEA (such as empirical crippling analyses). In any case, to satisfactorily achieve desired accuracy, many different types of FEMs are usually required of the same structure in addition to the 'loads model' to account for the multitude of failure possibilities.



HyperSizer solves this problem by coupling to a single, coarse finite element mesh. HyperSizer uses unique and innovative thermoelastic formulations for the generalized thermomechanical stiffness terms of stiffened or sandwich panels. These formulations include unsymmetric stiffened panel behavior such as that produced by hat, Z or J concepts.

 (Refer to the technical papers available from our downloads page)

 
 HyperSizer's general thermoelastic formulations are able to obtain the same solution with a coarse 2-D surface mesh as indicated in the color plot of this 3-D discretely meshed hat panel.

The resulting stiffness terms and thermal coefficients are assigned to the elements of the FEM and make it possible to get accurate, detailed structural results using a coarsely meshed, planar FEM of an entire airframe/engine structure.