Brittle fracture in PVC pipe material

Abstract

HSUEH-LEE SYNOPSISMethods to measure the plane strain fracture toughness (I&) of PVC pipe material, valid according to linear elastic fracture mechanics (LEFM), have been developed. As in metals practice, the crack tip plastic zone must be small compared to initial crack length, section thickness, and other specimen dimensions to achieve validity. Other conditions of test rate and temperature also must be fulfilled. K I , values vary from 2.8 to 4.0 MN m-.3R. Quantitative micromechanical analyses of the plastic flow regions on the fracture surfaces account for only a fraction of the measured toughness. Other deformation mechanisms (crazing) below but near the surfaces have been observed; apparently they absorb the balance of the work required to drive the stable crack. Under catastrophic, rapid crack propagation, only a single craze exists ahead of the crack tip; the multiple crazes disappear. Thus the dynamic fracture toughness may be several factors less than the static or stable value. tion rate), and temperature in addition to the material property itself [4].

Mechanical behavior and fracture characteristics of polymeric pipes under curved three point bending tests: Experimental and numerical approaches

“…In their work focusing on the brittle fracture process of PVC pipe material, McGarry et al [4] have only considered brittle failures, despite that PVC pipe materials may fail in a ductile manner in service.…”

“…Among thermoplastic materials, polyvinyl chloride (PVC) pipes are equally used for drinking and wastewater evacuation, window profiles, wire and cable insulation and medical devices [4,5,7], thanks to their mechanical and tribological properties [6][7][8][9][10]. PVC ⁎ Corresponding author.…”

Extensive testing on PVC sewer pipes towards identifying the factors that affect their operational lifetime

“…However, it has to be stressed that service temperatures can be lower than the tested ones, resulting in a more brittle behaviour and a reduced capacity of the pipe to absorb energy before fracturing (McGarry, Mandell, & Hsueh-Lee, 2007;Scholten, van der Stok, Gerets, Wenzel, & Boege, 2016;Visser, Bor, Wolters, Warnet, & Govaert, 2011). It is expected that, after a certain point, this brittleness will potentially cause issues concerning the pipe inspection and the placement of new household connections.…”

A review on the durability of PVC sewer pipes: research vs. practice

“…Apart from processing quality, temperature is also a critical factor concerning the mechanical properties of the material. Lower temperatures result in more brittle failures, whereas the amount of energy that can be absorbed by PVC pipes before fracture seems to reduce dramatically (McGarry, Mandell, & Hsueh-Lee, 1985;Scholten et al, 2016;Visser et al, 2011).…”