Comparative study of microlaser excitation thermography and microultrasonic excitation thermography on submillimeter porosity in carbon fiber reinforced polymer composites

Abstract

, "Comparative study of microlaser excitation thermography and microultrasonic excitation thermography on submillimeter porosity in carbon fiber reinforced polymer composites," Opt. Eng. Abstract. Stitching is used to reduce incomplete infusion of T-joint core (dry-core) and reinforce T-joint structure. However, it may cause new types of flaws, especially submillimeter flaws. Thermographic approaches including microvibrothermography, microlaser line thermography, and microlaser spot thermography on the basis of pulsed and lock-in techniques were proposed. These techniques are used to detect the submillimeter porosities in a stitched T-joint carbon fiber reinforced polymer composite specimen. X-ray microcomputed tomography was used to validate the thermographic results. Finally an experimental comparison of microlaser excitation thermography and microultrasonic excitation thermography was conducted.

Impact Modelling and A Posteriori Non-destructive Evaluation of Homogeneous Particleboards of Sugarcane Bagasse

“…In LLT, the heating provides a measure of the thermal impedance between the heated "spots" generated in a sample constituted by dispersed fibres into a matrix. This impedance The experimental setups (for LLT and LStT techniques) used in this work can also be found elsewhere [64].…”

“…In the set-up, an ultrasound excitation transducer with a pressure of 200 Pa was pressed against the sample and a burst of ultrasound waves was delivered to the SCB. Also in this case, interested readers can find the VT experimental setup used in [64].…”

Specific testing of textiles for transportation

“…In addition, new NDT techniques are continuously developed. For instance, a micro-vibrothermography device was designed to detect deep submillimeter flaws in stitched T-joint carbon fiber reinforced polymer (CFRP) composites (Zhang et al, 2016). A burst of ultrasound waves is delivered to the specimen with a 200 Pa ultrasound excitation transducer.…”

Enhanced Infrared Image Processing for Impacted Carbon/Glass Fiber-Reinforced Composite Evaluation

“…IRT involves different thermal excitation methods such as optical excitation thermography, ultrasonic excitation, laser excitation thermography and inductive thermography, etc. [ 6 , 7 , 8 ]. Advanced signal processing plays a very important role in IRT because the raw thermal images are time-domain sequences that can be post-processed in time-domain, or transformed to another such as the frequency-domain in Fourier transform analysis [ 9 , 10 ].…”