Consider the design of aluminum bicycle frames A prototype m

Consider the design of aluminum bicycle frames. A prototype model failed in fatigue after 16000 km of riding, whereas most steel frames can be ridden for over 60,000 km. Describe a design program that will solve this problem

Solution

1) Analysis of failure - failure mechanism (e.g. Fatigue, SCC, whatever) including design factors influencing failure mode and time to failure (bending, torsional moments, stress concentrations, joining procedures, etc.) important to determine why this reduced service life was not anticipated - What wrong with evaluation/testing procedures.

2) Stress distribution analysis on prototype design - Why did failure occur when and where it did? - remember, the object is not necessarily to eliminate failure but to postpone it.

3) Redesign options to at least extend time to failure to where it can compete with steel.

4) Some simulation of performance - computer modeling, FEA, whatever to test the various redesign concepts.

5) Develop a prototype testing procedure/device which will allow some estimation of service life.

6) Manufacture/construct and assemble prototype.

7) Test prototype and redesign if necessary (iterative/feedback design process)