软质泡沫聚合材料.使用恒定应变程序测定疲劳度

[中文适用范围]： 本国际标准规定了一种确定柔性多孔材料在重复压缩至固定应变水平时厚度损失的方法。 它对于柔性聚合物多孔材料制造中的质量控制特别有用。 另一种程序已经存在，如 ISO 3385：它通过样本的恒定应力加载而不是恒定应变来测量柔性聚合物多孔材料的疲劳特性。 它构成了 ISO 5999 材料分类系统的基础。 这两种疲劳程序相互补充，都可用于预测最终使用性能。 本国际标准中使用的程序和设备允许同时测试大量试件，而 ISO 3385 只允许在压缩装置下一次测试一个试件。 [外文原描述]： ISO 24999:2008 specifies a method for determining the loss in thickness of flexible cellular materials when compressed repetitively to a fixed level of strain. It is particularly useful for quality control in the manufacture of flexible polymeric cellular materials. Another procedure already exists as ISO 3385: this measures the fatigue characteristics of flexible polymeric cellular materials by constant-stress loading of the specimen rather than constant strain. It forms the basis of a material classification system in ISO 5999. These two fatigue procedures are complementary to each other and can both be useful in the prediction of end-use performance. The procedure and equipment used in this International Standard allow testing of a large number of test pieces at any one time, whereas ISO 3385 only allows testing of one test piece at a time under the compression device.