Ben Jar, PhD, PEng

Area of Study / Keywords

Mechanics And Materials Experimental Mechanics Fracture Mechanics Composites And Polymers Design And Manufacturing Additive Manufacturing

Research

My research is in the area of materials evaluation. I design test methods to assess effects of various parameters and processing conditions on material performance, especially when such information cannot be obtained from standard methods. The main objective of the testing is to identify criteria for deformation and failure, which are then implemented in computer models to evaluate their survivability in extreme environment.

I also build machines for the material testing. My team has designed and built devices for biaxial, impact and indentation loading to coupon specimens of polymers and fibre composites.

My current study is focused on deformation and fracture of polymers, fibre composites and rail steels. The research approach consists of experimental testing, computer simulation, and theoretical analysis, in order to explore the full range of material behaviour and to correlate the laboratory test results with the in-service performance.

Research in the following areas is available for graduate study. Please contact me for details.

• Characterization of viscous behavior of polymers and 3D-printed polymers
• Environmental stress cracking resistance of polymers
• Slow crack growth of polymeric materials
• Toughness of rail steels
• Design of a new test method to characterize environmental stress cracking resistance of polymers
• Delamination of fibre composites in shear mode

Selected Publications:

* P-Y B Jar, Revisiting creep test on polyethylene pipe – data analysis and deformation mechanisms. Polym Eng Sci 61, 586-599 (2021).

* Na Tan, P.-Y. Ben Jar (2020) “Deformation Transitions of Ethylene-Hexene Copolymers under Creep Loading,” Polymer (Guildford) 208, 122905.

* Y. Zhang and P.-Y. B. Jar, “Effects of Squeeze-off on Mechanical Properties of Polyethylene Pipes,” International Journal of Solids and Structures (IJSS) 135, 61-73 (2018).

* F. Yu, P.-Y. B. Jar, and M. Hendry, “Constitutive analysis of pressure-insensitive metals under axisymmetric tensile loading: a stress triaxiality-dependent plasticity damage model,” International Journal of Mechanical Sciences, 142-143, 21-32 (2018).

* Y. Zhang and P.-Y. B. Jar, “Time-Strain Rate Superposition for Relaxation Behavior of Polyethylene Pressure Pipes,” Polymer Testing 50, 292-296 (2016).

* Y. Zhang and P.-Y. B. Jar, “Phenomenological Modelling of Tensile Fracture in PE Pipe by Considering Damage Evolution,” Materials and Design 77, 72-82 (2015).

* P.-Y. B. Jar and W. Cao “Application of a New Mechanistic Approach to Measurement of Plane-Stress Fracture Toughness of Low-Density Polyethylene,” Engineering Fracture Mechanics 96, 179-191 (2012).

* P.-Y.B. Jar, R. Adianto, and S. Muhammad, "A mechanistic approach for determining plane-stress fracture toughness of polyethylene," Engineering Fracture mechanics 77, 2881–2895 (2010).

* H. J. Kwon and P.-Y. B. Jar, “On the Application of FEM to Deformation of High-Density Polyethylene,” International J of Solids and Structures 45 (11),3521-3543 (2008).

* Chengye Fan, P.-Y. Ben Jar and J.-J. Roger Cheng, "Cohesive Zone with Continuum Damage Properties for Simulation of Delamination Development in Fibre Composites and Failure of Adhesive Joints," Engineering Fracture mechanics 75 (13), 3866-3880 (2008).

* H.J. Kwon and P.-Y. B. Jar, "Application of Essential Work of Fracture Concept to Toughness Characterization of High-Density Polyethylene," Polym. Eng. Sci. 47(9),1327-1337 (2007).

* C. Fan, P.-Y. B. Jar, J.J. R. Cheng, “Energy-based analysis of delamination development on fibre-reinforced polymers (FRP) under 3-point bending test,” Compos. Sci. Tech. 66, 2143-2155 (2006).

* H.J. Kwon and P.-Y. B. Jar, “Fracture Toughness of Polymers in Shear Mode,” Polymer 46 (26), 12480-12492 (2005).

* T. Kuboki, K. Takahashi, P.-Y. B. Jar and T. Shinmura, “Mechanical Deformation of High-Impact Polystyrene under Uni-Axial Tension at Various Strain Rates,” Macromolecules 35(9),3584-3591(2002).

* P. Compston, P.-Y. B. Jar, P. Burchill and K. Takahashi, “The effect of matrix toughness and loading rate on the mode II interlaminar fracture toughness of glass-fibre/vinylester composites,” Compos. Sci. Tech., 61, ER2, 321-333 (2001).

* P.-Y. B. Jar, M. Todo, K. Takahashi, K. Konishi and T. Shinmura, “Finite Element Analysis to Verify Craze Suppression for Matrix Shear Yielding in Rubber-Modified Glassy Polymers”, Plastics, Rubber and Composites (PRC) 30(3), 101-109 (2001).

MEC E 362 - Mechanics of Machines

Velocities and acceleration in plane mechanisms, balancing of rotating and reciprocating machinery, gears and gear trains. Prerequisite: MEC E 250.

MEC E 687 - Introduction to Impact Dynamics of Materials

Elastic waves, plastic waves, shock waves and stress wave propagation in solids. Low velocity impact on fibre composite materials and failure criteria. High velocity impact mechanisms and fracture criteria. Impact penetration mechanics. Dynamic deformation and fracture of materials. Prerequisite: MEC E 480 or consent of Instructor.

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