Pugna Adrian, Negrea Romeo, Linul Emanoil, Marsavina Liviu
Department of Management, University Politehnica Timisoara, Blvd. M. Viteazu, No. 1, 300222 Timisoara, Romania.
Department of Mathematics, University Politehnica Timisoara, Pta. Victoriei, No. 2, 300006 Timisoara, Romania.
Materials (Basel). 2020 Oct 30;13(21):4868. doi: 10.3390/ma13214868.
The published data on the experimentally determined fracture toughness of foams are based on a small number of specimens, having a lack of statistical consistency. The paper proposes a statistical approach on the fracture toughness results of rigid polyurethane (PUR) foams of three different densities. Five types of fracture tests were considered. The results were statistically analyzed using six types of regressions and a meta-analysis to identify the factors influencing the fracture toughness. The statistical analysis indicates that the fracture toughness represents a material property because does not depend on the specimen type. The density plays a major role in the fracture toughness of PUR foams. The irregular shape of the cells induced small anisotropy for low-density foams (100 kg/m and 145 kg/m). This effect could not be observed for the foam with 300 kg/m density, for which the cells have a more regular spherical shape. The statistical analysis indicates that the influence of the loading speed is very weak.
已发表的关于泡沫材料实验测定断裂韧性的数据基于少量样本，缺乏统计一致性。本文针对三种不同密度的硬质聚氨酯（PUR）泡沫的断裂韧性结果提出了一种统计方法。考虑了五种类型的断裂试验。使用六种回归和荟萃分析对结果进行统计分析，以确定影响断裂韧性的因素。统计分析表明，断裂韧性代表一种材料特性，因为它不依赖于试样类型。密度在PUR泡沫的断裂韧性中起主要作用。对于低密度泡沫（100 kg/m³和145 kg/m³），泡孔的不规则形状导致了较小的各向异性。对于密度为300 kg/m³的泡沫，这种效应未被观察到，其泡孔具有更规则的球形形状。统计分析表明加载速度的影响非常微弱。
