本文件规定了三种测定纸张和纸板弯曲刚度的试验方法。试验方法因加载模式的类型不同而不同，因此产生了两点、三点和四点弯曲试验方法。 对于厚度较低的纸张和纸板，两点弯曲法和三点弯曲法都适用。 对于厚度较大的瓦楞纤维板和纸板，建议采用四点弯曲法。 测量条件的定义应确保试样在试验过程中不会受到任何明显的永久变形，也不会超出计算弯曲刚度公式的有效范围。 在这些弯曲试验中，纸张和纸板的试样被视为材料强度科学定义的“梁”，参见参考文献[2]交叉引用:ISO 186ISO 3034ISO 534ISO 187DIN 53121ISO 7500-1购买本文件时可获得的所有当前修改件包括在购买本文件中。

This document specifies three test methods for determining the bending stiffness of paper and paperboard. The test methods differ in the type of loading mode, thus giving rise to the two-point, three-point and four-point bending test methods. For paper and paperboard in a low thickness range, the two-point bending method and the three-point bending method are suitable. For corrugated fibreboard and board with a higher thickness, the four-point bending method is recommended. The measurement conditions are defined in such a way that the test piece is not subjected to any significant permanent deformation during the test, nor is the range of validity of the formulae for calculating the bending stiffness exceeded. In these bending tests, the test pieces of paper and board are regarded as "beams" as defined by the science of the strength of materials, see Reference [2]Cross References:ISO 186ISO 3034ISO 534ISO 187DIN 53121ISO 7500-1All current amendments available at time of purchase are included with the purchase of this document.