Effects of strain rate and temperature on tensile properties of CPVC pipe material

In this study, crosshead speed and temperature dependence of tensile properties of CPVC pipe material is investigated. Standard ASTM tensile specimens are used. Temperatures ranging from –10 to 70°C and three crosshead speeds (5, 50 and 500 mm min^-1) are considered in the testing programme. The tensile test results showed that a reduction in temperature and an increase in crosshead speed have favoured brittle fracture. The yield stress and elastic modulus decreased logarithmically with decreasing crosshead speed and linearly with increasing temperature. The strain rate–temperature superposition held for both yield stress and modulus of elasticity and master curves were developed for both properties using a temperature based shift factor. A single power law relationship is developed between the shear strength and the shear modulus for all temperatures and strain rates. The value of fracture strain remained almost constant with crosshead speed at 50°C and below. At 70°C however, an enhancement of fracture strain occurred with increasing crosshead speed between 5 and 50 mm min^-1 then stabilised with further increasing crosshead speed.