FINITE ELEMENT ANALYSIS

-Second year

-Individual project

Finite element analysis is a computational method used to assess how solid bodies may react to external conditions such as a force. For the FEA module each student was required to design and 3D model a tandem bike frame which would then be subject to operational and static loads expected from normal riding conditions. Using complex computer aided engineering (CAE) tools to analyse where stresses were concentrated, students were tasked with creating three iterations attempting to improve the performance of the frame each time. 

My most successful iteration was able to sustain the weight of two 100kg riders producing a maximum stress of 63MPa and a maximum displacement of 2.21mm. The frame did not fail after 1,000,000 cycles alternating between maximum and minimum stresses, and total life cycle (number of predicted cycles before failure) was 40,000,000+.

It was also important to ensure the natural frequency of the frame was not close to the expected excitation frequency to eliminate the possibility of resonance. Resonance is the cause of failure in many structures such as the Tacoma bridge collapse. Techniques such as mesh refinement were used to more accurately analyse areas of high stress concentration.

Mesh analysis
Mesh analysis

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Initial 2D sketch
Initial 2D sketch

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Von Mises chart
Von Mises chart

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Mesh analysis
Mesh analysis

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Overall the project taught me that CAE techniques can be incredibly effective testing under real life loading conditions  while saving on physical prototyping and manufacturing costs.