Creep and creep-rupture characteristics of some riveted and spot-welded lap joints of aircraft materials

Author / Creator

Mordfin, Leonard, author

Available as

Online

Summary

Equipment and test techniques which were used in the creep testing of lap joints are described. Riveted aluminum-alloy joints fabricated from 75S-T6 and 24S-T3 sheet with 24S and 24S-T31 rivets wer...

Equipment and test techniques which were used in the creep testing of lap joints are described. Riveted aluminum-alloy joints fabricated from 75S-T6 and 24S-T3 sheet with 24S and 24S-T31 rivets were tested at 300, 400,and 500 degrees F. Spot-welded joints of 1/4-hard, type 301 stainless steel were tested at 800 degrees F. Each type of Joint was also tested in tension at room temperature.

The test results show that the creep of the riveted joints is considerably greater than the creep of the unriveted sheet although not so large that the creep of the sheet is negligible compared with that of the joints. The shapes of the creep curves of the joints indicate that a correlation may be possible with the creep properties of its ccmponent materials.

The limited data obtained indicate that the creep-rupture strength of a riveted joint may be approximated by assuming the creep-rupture efficiency of a joint at any temperature to be equal to the room-temperature efficiency. An empirical relation based on the experimental results is proposed to give more accurate estimates of the creep-rupture strength.

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