Analysis of tensile test results for poly(acrylonitrile‐butadiene‐styrene) based on Weibull distribution

Abstract

Statistical analysis based on two‐parameter Weibull distribution was applied to poly(acrylonitrile‐butadiene‐styrene) to characterize involvement of two damage types in tensile test specimens, which appear as tiny strips and uniform whitening, respectively. Analysis using Weibull distribution suggests that the probability density functions (PDF) for extension at break and total energy consumption (named toughness) give distinctively different characteristics between the two damage types. PDF curve for the tiny strips consists of a sharp peak, whereas that for the uniform whitening a broad hump. Using two‐group mixed Weibull distribution, effect of pre‐existing damage on the fracture process was examined. The PDF curves show that presence of one damage type (e.g., uniform whitening) tends to suppress generation of the other damage type (e.g., tiny strips) even in a test condition that would have favored the latter in virgin specimens. Involvement of the two damage types was quantified using portion for each subpopulation from the Weibull distribution analysis. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers

Structural Heterogeneity Dependence of the Fracture Feature Distribution in the Tensile Elongation of Microinjection Molded Polyethylene

“…To investigate the scattered fracture behaviors, one often utilizes a statistical method with a large number of repeated measurements. Concerning the distribution of fracture features, a Weibull function can fit the distribution well for the brittle or quasi-brittle materials, − whereas a Gaussian function works better for the ductile materials. − In some cases, there exists a bimodal distribution of fracture characteristics for ductile polymers, , which implies a nonuniformity of microstructure before or during deformation process. Furthermore, a non-Gaussian distribution of failure properties was observed in the tensile fracture of high-density polyethylene (HDPE) specimens in our previous study, signifying the existence of a structural defect in the samples …”