Effects of strain rate and temperature on fracture toughness and tensile properties of CPVC

(2005) Effects of strain rate and temperature on fracture toughness and tensile properties of CPVC. Masters thesis, King Fahd University of Petroleum and Minerals.

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In recent years, there has been a large increase in the use of polymers in engineering applications. Along with this increase use will almost assuredly come failures. Chlorinated-PVC (CPVC) is a material designed to withstand higher temperature than PVC. For this reason, understanding the mechanical properties under different loading rates and temperatures has become increasingly important. In this thesis work, strain rate (crosshead speed) and temperature dependence of fracture toughness and tensile properties of CPVC pipe material is investigated. Single-Edge-Notch Bending (SENB) and tensile specimens are used for fracture toughness and tensile tests, respectively. Five temperatures (-10, 0, 23, 50 and 70℃) and three crosshead speeds (5, 50 and 500 mm/min) are considered in this study. The results showed that both ductile and brittle fracture modes are possible. At 50℃, brittle to ductile transition behavior is observed. A reduction in temperature and an increase in crosshead speed have favored brittle fracture. The yield stress and elastic modulus decreased with decreasing crosshead speed and increasing temperature. However, the value of fracture strain remained almost constant with crosshead speed at room temperature and below. At 50 and 70℃, an enhancement of fracture strain occurred with increasing crosshead speed between 5 and 50 mm/min then stabilized with further increasing crosshead speed. The value of fracture toughness increased with crosshead speed between 5 to 50 mm/min for all temperatures. However for the range of 50 to 500 mm/min, it reduced slightly at low temperatures (-10, 0 and 23℃) and enhanced at high temperatures (50 and 70℃) with increasing crosshead speed. It increased with temperature then it dropped at 70℃ for all crosshead speeds. The crosshead speed and temperature effect is explained in terms of the crack tip blunting, crack tip plastic zone and fracture surface condition. Moreover, the relationships between fracture toughness and toughness modulus were explained.

Item Type: Thesis (Masters)
Subjects: Mechanical
Divisions: College Of Engineering Sciences > Mechanical Engineering Dept
Committee Advisor: Merah, Nesar
Committee Members: Khan, Zafarullah and Gasem, Zuhair M.
Depositing User: Mr. Admin Admin
Date Deposited: 22 Jun 2008 17:06
Last Modified: 01 Nov 2019 17:02
URI: http://eprints.kfupm.edu.sa/id/eprint/10506