Hey guys im a first timer here. I need some help with a couple of questions im quite stumped.(adsbygoogle = window.adsbygoogle || []).push({});

1. A bar in a 2-D loading system is 1 metre long and 20 millimeters square in section before loading. Determine the change in its "x" and "y" dimensions if E=200GPa and Poisson's Ratio is 0.3

The force acting in the "x" direction is 60KN and in the "y" direction 40KN.

ok, i know i have to find the stress in the x and y directions first. By dividing the Force by the Area of the bar. e.g. 60000 newtons/ mm2.

i cant seem to work out what the area of the bar would be, i dnt understand "20 millimeters square in section" i need the area in mm2 also.

Then i would work out the combined strain in the xx direction and yy direction.

Finally to work out the change in length i multiply the strain by the original length.

Any feed back would be great, thanks

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# Homework Help: Mechanical Principles

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