FEM structural analysis
The aim of structural analysis is to predict the level of stresses and deformations of an object depending on its material properties, load type and the way it is fixed. That enables determination if the design is strong enough to support the designed loads or if the material is used economically.
Owing to their geometrical complexity, most of the structures need to be analysed using specific computer programs and numerical. The most common approach is the so-called finite element method, FEM. The object of our interest is divided to multiple simpler objects (these are the finite elements). Their mechanical interactions are the subject of our calculations and are found in an approximate manner using specialized computational model.
Benefits of an FEM structural analysis:
- prediction of critical areas in the project, including stress concentration zones,
- minimization of the material use and cost,
- shape optimization of the structure so that internal loads are minimized.
Types of FEM consulting services offered by QuickerSim:
- linear static analyses
- heat-dependent loads
- non-linear analyses (large deformations, contact, plasticity)
- analysis coupled with fluid flow (so-called Fluid Structure Interaction, FSI)
- optimization analysis, recommending geometric modifications
We offer the analyses as stand-alone consultancy services as well as perform them in comprehensive projects.
The Polish Air-Force Research Institute ordered a design of a gas micro-turbine at QuickerSim. Apart from CFD simulations QuickerSim had to perform the strength analysis of the proposed design.
These were critical because of the large centrifugal forces – the turbine was supposed to revolve at several tens of thousands rev./min. The most loaded part of the design was the junction between the internal ring and the turbine blades. Especially the slim trailing-edge experienced a large stress-concentration factor.
Two actions were recommended. On one hand, the entire junction was rounded while on the other, the aft part was cut-off. However, because of a relatively small space between the inner and outer rings every contraction of the flow space resulted in some deterioration of the turbine’s performance. Thus the rounding’s radius had to be minimized. Only a detailed FEM analysis could point to the exact dimension.;
Pic. 1 Stress concentration at the trailing edge-inner ring junction
Pic. 2 Undercut and rounded connection of the turbine blade and the inner ring – front and back views