Thermomechanics and Infra-Red Imaging

Optimization of Transient Thermography Inspection of Carbon Fiber Reinforced Plastics Panels Part 1

ABSTARCT Transient thermography non-destructive evaluation methods are being used in aerospace industry to inspect flaws and damages for various composite materials. The purpose of this paper is to establish a set of guidelines for testing Carbon Fiber Reinforced Panels (CFRP) panels using infrared thermography. These guidelines insure that the inspection process is efficient and effective. […]

Optimization of Transient Thermography Inspection of Carbon Fiber Reinforced Plastics Panels Part 2

Experiments Set-up and Test Knowing the type of materials being tested is important to obtaining accurate results from the experiments. Also the more known about a material, more conclusions can be made from experimental data. With this it is important to know the equipment being used and how to set it up properly. Combining these […]

Experimental investigation of thermal effects in foam cored sandwich beams

ABSTRACT Polymer foam cored sandwich structures are commonly used in applications where mechanical loads and elevated temperatures form the normal service conditions. The temperature sensitivity of the mechanical properties of the polymer foam cores leads to compromised mechanical performance of the overall sandwich structure at elevated temperatures. So far this phenomenon has primarily been investigated […]

Intelligent Non-Destructive Evaluation Expert System for Carbon Fiber Reinforced Plastics Panel Using Infrared Thermography

ABSTARCT This research developed a reliable intelligent non-destructive evaluation (NDE) expert system for Carbon Fiber Reinforced Panels (CFRP) panels based on infrared thermography testing (IRT) and post processing by means of fuzzy expert system technique. Data features and NDE expert knowledge are seamlessly combined in the intelligent system to provide the best possible diagnosis of […]

Successful Application of Thermoelasticity to Remote Inspection of Fatigue Cracks Part 1

ABSTRACT A new remote nondestructive inspection technique based on thermoelastic temperature measurement by infrared thermography was developed for the detection of fatigue cracks in steel bridges. Fatigue cracks were detected from localized thermoelastic temperature changes at crack tips due to stress singularities generated by wheel loading from traffic on a bridge. Self-reference lock-in data-processing technique […]

Successful Application of Thermoelasticity to Remote Inspection of Fatigue Cracks Part 2

Remote detection of fatigue crack Remote detection of fatigue cracks in steel deck in actual steel bridge in-service was conducted by the self-reference lock-in thermography with telescope lens as shown in Fig. 8. Infrared measurement was conducted from distant places in distances of 8m and 12m. Thermoelastic temperature change near the crack tip under variable […]

Investigation of residual stress around cold expanded holes using thermoelastic stress analysis Part 1

ABSTRACT Thermoelastic stress analysis (TSA) is a well established tool for non-destructive full-field experimental stress analysis. In TSA the change in the sum of the principal stresses is derived and it is generally accepted that the TSA relationship does not allow the evaluation of residual stress, which is essentially a mean stress. However, modifications to […]

Investigation of residual stress around cold expanded holes using thermoelastic stress analysis Part 2

EXPERIMENTAL PROCEDURE The plate specimens used in this work have been chosen to be representative of in-service applications, whilst at the same time realising the limitations associated with the load capacity of test machines and loading jigs (shown in Fig. 3 and Table 1). Aluminium plate specimens were manufactured with dimensions of 300 mm by […]

TSA Analysis of Vertically- and Incline-loaded Plates containing Neighboring Holes

ABSTRACT This paper presents an effective way to determine the individual stresses in arbitrarily-loaded multiply-perforated finite plates whose various size cutouts are randomly distributed. Thermoelastic stress analysis (TSA) is used such that the recorded temperature data are processed utilizing an Airy’s stress function. Advantages of TSA include full-field, non-contacting, nondestructive, no surface preparation other than […]

Examination of Crack Tip Plasticity Using Thermoelastic Stress Analysis

INTRODUCTION Thermoelastic Stress Analysis (TSA) is based on the principle that under adiabatic and reversible conditions, a cyclically loaded structure experiences temperature variations that are proportional to the sum of the principal stresses. These temperature variations may be measured using a sensitive infra-red detector and thus the cyclic stress field on the surface of the […]

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