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 金属板材的成形极限是板材成形领域中的重要性能指标和工艺参数。目前，国内外均已开展以厚度减薄率作为成形极限判据的成形极限试验模拟研究，其厚度减薄率的测试过程较为复杂，不适合实验室大批量检验工作。提出了2种金属板材拉伸厚度减薄率的测试方法，一种为人工测试断后试样断口附近厚度分布，得到厚度减薄率变化曲线；另一种方法是通过公式推导，将厚度减薄率与试样纵向应变联系起来，通过测试纵向应变，得到集中性失稳前的厚度减薄率变化规律。

Study of Thickness Thinning Rate Testing of Sheet Metal

Forming limit is the most important performance and process parameter in sheet metal forming.Nowadays,the research about forming limit experimental simulation has been started with the thickness thinning rate as forming limit criterion.However,it is very complicated of the thickness thinning rate testing which is not suitable for the testing in the industry.Two methods have been put forward for thickness thinning rate testing.First,the thickness thinning rate curve can be acquired by testing the thickness distribution near the broken area.The second method is associating thickness thinning rate with longitudinal strain by computation.So that the change law of thickness thinning rate before concentrative instability can be attained by longitudinal strain testing.