소성∙가공 (Transactions of Materials Processing)
- 제3권3호
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- Pages.320-334
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- 1994
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- 1225-696X(pISSN)
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- 2287-6359(eISSN)
평면응력하에서의 직교이방성 대칭축의 회전
Rotation of Orthotropy Axes under Plane Stress
초록
A set of full size cold rolled steel sheets has been prestrained in the direction of rolling by uniform tensile elongation of 3% and 6%. Then mid-sized tensile specimens were cut from each of the full size sheets at 30, 45, 60 and 90 degrees to the rolling direction. The mid-sized tensile specimens were then prestrained again by uniform tensile elongation by 1%, 2%, 5%, 10% and 15%. finally, miniature tensile specimens were prepared from each of the mid-sized specimens at every 10 degrees to the specimen axis. From the tensile tests on miniature specimens material's hardening behavior under non-proportional loading has been investigated. There are a number of new observations which has not been known to the authors before current work. One of them is continuous reservation of orthoropic symmetry during tensile elongation of mid-sized specimens. Another is continuous rotations of orthotropy axes. Existing theories seem to fail to explain this observations. A new model is proposed in relation to the rotation of orthotropy axes.
키워드