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The use of thermoelastic stress analysis for stress distribution evaluation of an industrial equipment under regular operating conditions

Misiewicz Robert, Moczko Przemyslaw, Boyce Bradley

Archives of Civil and Mechanical Engineering

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2022

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Vol. 22, no. 3

art. no. e106

EN

Thermoelastic stress analysis (TSA) is an experimental technique enabling the determination of stress pattern and level. Because of the dependence of the technique on a temporally changing load on the target structure, it is mainly considered as a technique suited to the laboratory, and therefore there is a dearth of real-world industrial applications. An experimental study of TSA applicability in determining the stress level distribution in a heavy industrial equipment joint (a bucket wheel excavator joint) under ordinary operating conditions was conducted. In the research, TSA and strain gauge measurements were validated with numerical computations. As the first step of validation, a numerical finite element analysis (FEA) was implemented. The authors then introduced an innovative approach to calibrating TSA results, which implements Rainflow decomposition of strain gauge measurements. Furthermore, a numerical validation approach based on modal frequency response analysis was implemented. Both the experimental and numerical approaches gave remarkably similar results, thereby confirming the possibility of effective use of thermoelastic stress analysis in industrial applications outside the laboratory.

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Stress analysis of total hip arthroplasty with a fully hydroxyapatite-coated stem: comparing thermoelastic stress analysis and CT-based finite element analysis

Watanabe Ryunosuke, Mishima Hajime, Takehashi Hironori, Wada Hiroshi, Totsuka Sho, Nishino Tomofumi, Yamazaki Masashi, Hyodo Koji

Acta of Bioengineering and Biomechanics

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2022

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Vol. 24, no. 2

47--54

EN

The aim of this study was to evaluate the stress distribution in a synthetic femur that was implanted with a fully hydroxyapatite- coated stem using thermoelastic stress and finite element analyses, and to clarify the differences in the stress distributions between these two methods. Methods: Thermoelastic stress analysis is a stress-analysis technique that employs the thermoelastic effect. Sinusoidal vertical loads were applied to the head of the stem placed on the synthetic femur, and surface stress distribution images were acquired using an infrared stress measurement system. The finite element model for the synthetic femur and stem were set up similarly to the thermoelastic stress analysis experiment, and vertical load was applied to the head of the stem. Surface stress distribution and stress values obtained via these two methods were compared. Results: Thermoelastic stress analysis showed that compressive and tensile stresses were distributed from the proximal femur to the diaphysis, not only on the medial and lateral surfaces, but also on the anterior and posterior surfaces. However, finite element analysis showed that compressive stress was not distributed on the anterior and posterior surfaces of the femoral intertrochanter. The stress values of thermoelastic stress analysis tended to be higher in the proximal femur than that obtained via the finite element analysis. Conclusions: The surface stress distribution obtained by these two methods were different specifically in the proximal femur. Our results imply that thermoelastic stress analysis has a better potential than finite element analysis to show the surface stress distribution that reflects the stem design.

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Wykorzystanie efektu termosprężystego do określenia rozkładu naprężeń w próbce z karbem

Misiewicz R., Moczko P.

Przegląd Mechaniczny

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2018

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nr 5

40--44

PL

W pracy przedstawiono wyniki badań potwierdzających możliwość zastosowania efektu termosprężystego do identyfikacji rozkładu naprężeń w próbce z karbem prostokątnym, zaokrąglonym. Zamieszczono także przegląd historyczny rozwoju termosprężystej analizy naprężeń, jak również jej podstawy teoretyczne. Wyniki badań eksperymentalnych porównano z wynikami obliczeń wytrzymałościowych za pomocą metody elementów skończonych.

EN

In this paper brief Thermoelastic Stress Analysis history and basic principles were introduced. Author also carried out thermoelastic research of blended rectangle notched specimen and Finite Element Analysis comparision. Research confirmed that it is possible to determine stress distribution in the specimen by TSA.

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Human pelvis loading rig for static and dynamic stress analysis

Zanetti E.M., Bignardi C., Audenino A.L.

Acta of Bioengineering and Biomechanics

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2012

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Vol. 14, no. 2

61-66

EN

This work is aimed at designing and constructing a loading rig for the synthetic hemi-pelvis; this system has been conceived with the goal of applying differently oriented articular forces in order to experimentally test the stress distribution and the stability of surgical reconstructions like, for example, hip arthroplasty or pelvic fixation. This device can be interfaced with a usual loading machine; it preserves the anatomy of the hemi-pelvis; it is simply constrained and it allows the simulation of all physiologic activities. Moreover, the visual accessibility of the peri-acetabular area has been guaranteed and this is imperative in order to be able to perform full-field analyses like a thermoelastic or photoelastic stress analysis. First experimental trials have shown a good repeatability of loading–unloading cycles (<1.2%), a low hysteresis (<2.4%) and a good dynamic behaviour (up to 10 Hz loading frequencies).