估计金属板料弯曲时的坯料长度往往采用表格法,经验法或试凑法。但是,这些方法一般来说是不准确的,这是因为坯料的长度不仅仅取决于弯曲半径、材料厚度和弯曲角度,而且取决于材料的性能。一种较好的方法是推导出适用所有材料的一系列公式,用这些公式来计算弯曲允许偏差和弯曲长度。如果已知材料的强度和延伸率,即可直接使用这些公式进行计算;否则可通过简单的弯曲试验确定材料的性能,然后用这些公式进行计算。假如材料弯曲的中性面恰好在板厚的中心线上(如图所示),那么弯曲长度的计算式为: It is estimated that when the sheet metal bending the length of the blank form is often used, empirical method or try to make law. However, these methods are generally inaccurate because the length of the blank depends not only on the bend radius, material thickness and bend angle, but also on the properties of the material. A better approach is to derive a series of formulas that apply to all materials and use these formulas to calculate the allowable deflection and the length of the bend. If you know the strength and elongation of the material, you can use these formulas directly to calculate; Otherwise, you can determine the material properties through a simple bending test, and then use these formulas to calculate. If the curved neutral surface of the material is exactly on the centerline of the plate thickness (as shown), the bending length is calculated as: