Dr Hafiz Ali

Summary

Hafiz is currently working on an EU funded consortium involving developing nonlinear ultrasonic techniques to allow the determination of bond strength in composite structures. The key research challenges are interpreting the complex nature of the transmitted nonlinear signal and optimizing the operating point selection for thin specimens.

Main challenges include:

• Experimental demonstration of various nonlinear ultrasonic techniques in thin specimens
• Development of models to allow easy selection of a guided wave operating point for inspection of thin components
• Usage of nonlinear guided wave inspection techniques to investigate the levels of nonlinearity present in thin composite specimens of varying bond strength.

Biography

Hafiz Ali completed his BSc with Honours in Indurstrial and Manufacturing Engineering (IME) from University of Engineering and Technology(UET) Lahore, Pakistan in 2004. He then secured MSc with Merit in Advance Manufacturing Management and Technology (AMMT) from University of Surrey, UK in 2006. Hafiz, during his PhD from University of Surrey, designed and manufactured a novel loading configuration to investigate and characterise the behaviour of the extremely important commercial polymer, FM-73M, under mixed-mode loading –applied both quasi-statically and cyclically. Under quasi-static testing, the strain energy release rate components at fracture were presented in a conventional G_I (mode I) - G_II (mode II) failure envelope using closed-form Linear Elastic Fracture Mechanics (LEFM) methods. The Virtual Crack Closure Technique (VCCT) was implemented in ANSYS and used to validate the calculated strain energy release rate components obtained for the range of loadings applied by the designed novel loading technique. While under fatigue testing, Paris law is used to present results for crack growth rate. For the quantitative description of the mixed-mode crack growth, generalized forms of the Paris relation are developed in which the Paris contants vary in a non-monotonic way.

Keywords

• Non-linear Ultrasonic Techniques
• Guided waves
• Bond strength
• Adhesive Bonding Technology
• Composite Structures
• Manufacturing Processes

Memberships

Organisations

Department of Mechanical Engineering

Other sites

• Mecheng

Research Groups

• Advanced Composites Centre for Innovation and Science (ACCIS)
• Solid Mechanics
• Dynamics and Control
• Ultrasonics and NDT