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 采用动态应变测量方法对成形极限曲线（FLC）检测中网格的大小，测量的时机(破裂前或破裂后测量)，测量的位置等因素进行了试验研究。研究结果表明，试样破裂前和破裂后测量的应变，以及使用不同大小的网格测量的结果都存在较大的差异，测量位置的不同会导致应变路径存在差异，影响FLC的准确度。最后将这些测量结果绘制的FLC同采用最佳反抛物线拟合计算得到的FLC进行了比较，分析了彼此的差别，并对FLC的检测提出了一些建议。

Research of Influence factors in FLC Determination

The influence factors, such as grid size, evaluating phase and evaluating position,in determination of forming limit curves (FLCs) were researched by dynamic strain determination method. It is shown that the strains obtained before fracture or after fracture, and measurement with small size grid or large size grid will differ greatly. Moreover, measurement at different evaluating positions over the specimen surface leading to different strain paths will also affect the accuracy of FLC. The FLCs plotted with the measured data were compared with the FLC calculated through best inverse parabola fitting. Finally, the difference between the measured data and the calculated data was analyzed, and some proposals in FLC determination are given.