Bolted Joint Analysis

A bolted joint connecting the high speed compressor shaft to the turbine shaft in a jet engine was analyzed to validate a redesign in the flange fillet of the turbine shaft.

A sector model of the bolted joint assembly was generated using a mapped brick mesh. A very fine mesh was created in the area of concern, eliminating the need for a submodel, with transition to a coarser mesh away from the redesigned fillet. Node to node gap elements were used at all part interfaces.

Cyclic symmetry was utilized at sector planes due to application of non-axisymmetric torque loads. Boundary conditions from a previously performed 2D analysis was mapped to cut planes in the compressor and turbine shafts. Frictional effects were included.

Steady-state stress analysis was performed for preload, speed plus pressure, and speed plus pressure plus torque conditions. Stresses and gap force summations were reported. Belcan’s analysis demonstrated that the fillet redesign was acceptable.