• Bayat, M.
• Safizadeh, Mir Saeed
• Moradi, Morteza

Abstract

In recent years, the increasing use of composite materials has resulted in an increased attention for calculating residual stress in the composite structure. Meanwhile, reliable measurement and prediction of residual stress remain a challenge for studying the composite behavior. Due to the fact, that destructive methods can cause additional stress in addition to existing residual stress, the use of non-destructive methods is more reliable and efficient in the industry. This paper presents a new non-destructive method for monitoring stress changes in Carbon Fiber Reinforced Plastic (CFRP) composites using pulsed thermography technique. By the analysis of different thermal emission, it is possible to measure the stress on the epoxy layer and on the carbon fiber. Numerical models using finite elements have been used to determine the behaviour of the thermal emission from a composite component subjected to different tensile stresses. The experimental measurements have been performed to verify the numerical results. In the experiment cases in which the tensile stress is constant, some differences are observed. Whereas, the thermography measurements show a linear increase of the temperature response with rising tensile stress, the accurate temperature measurements are quite limited due to the camera's low sensitivity. The experimental results revealed that the finite element simulations obtained in the present work are capable of detecting the stress (residual stress) in the carbon fiber/epoxy composites.

Topics

• impedance spectroscopy
• polymer
• Carbon
• experiment
• simulation
• composite
• thermography