Behaviour of aluminium alloy (Topic: 12034)

An aluminium alloy structure under repeated stress applications will fail even though the maximum stress applied is well below the static strength of the aluminium alloy.

An increase in repetitions will decrease the stress level where the failure occur. This is shown in the diagram below.

This diagram is called a S-N-curve. There will be many S-N-curves. One for each condition dependent on:

- Alloy

- Type of weld

- Area of welding

- Other attachments

References: [18]