Papers by Keyword: Stress Separation

Abstract: Recently, the influence of heat conduction has been considered to be a big problem. Then, the influence of heat conduction was investigated by the experiment which changed the material, thickness of the specimen and frequency of a cyclic load. Then, the infrared hybrid method was developed to separate individual stress components. However, it has the influence by heat conduction in the infrared stress measuring method. Therefore, an error will arise in the infrared hybrid analysis. Then, the system which corrects the error by the inverse analysis was developed. Thereby, the accuracy of the stress intensity factor was able to be raised. Furthermore, the accuracy of hybrid method considering to heat conduction was discussed in comparison with the 3-D finite-element analysis and 2-D hybrid method.

Abstract: Thermoelastic Stress Analysis (TSA) information is proportional to the change in the sum of the principal stresses. Since one often has to know the magnitude of individual stresses, additional experimental methods or data are frequently required to ‘separate the stresses’. This paper demonstrates the ability to evaluate individual stresses in a uniaxially-loaded finite plate with a central circular hole from TSA-recorded information without supplementary experimental data. Measured temperatures are combined with an Airy stress function and some limited traction-free conditions. The present technique does not presuppose knowing the external geometry or boundary conditions, overcomes traditional difficulties of unreliable edge data, and reduces the number of coefficients needed by satisfying the traction-free conditions analytically on the edge of the hole. Attention is paid to determining an appropriate number of the real (not complex) Airy coefficients.

Abstract: Influence of the frequency to the temperature image obtained by an infrared thermography was investigated using specimens of three kinds of materials at four kinds of frequencies of the cyclic load. Then, the infrared hybrid method was developed to separate individual stress components. However, the influence of heat conduction is inevitable in the infrared stress measurement method. Therefore, an error arises in the infrared hybrid analysis. Then, the system which corrects the error by the inverse analysis was developed. Thereby, the accuracy of the stress intensity factor was able to be raised. Furthermore, the accuracy of hybrid method considering to heat conduction was discussed in comparison with the 3-D finite element analysis and 2-D hybrid method.

Abstract: The thickness dependency of the temperature image obtained by an infrared thermography was investigated using specimens with three kinds of materials and four kinds of the thickness of the specimen. Then, the infrared hybrid method was developed to separate individual stress components. However, it had the influence by heat conduction in the infrared stress measuring method. Therefore, an error will occur in the infrared hybrid analysis. Then, the system which corrected the error by the inverse analysis was developed. Thereby, the accuracy of the stress intensity factor was able to be raised. Furthermore, the accuracy of hybrid method considering to heat conduction was discussed in comparison with the 3-D finite-element analysis and 2-D hybrid method.