| Author: | Liang, Zi-hao |
| Title: | True stress-strain characteristic of s275 and s690 steel materials |
| Advisors: | Chung, K. F. (CEE) |
| Degree: | M.Sc. |
| Year: | 2019 |
| Subject: | Steel, Structural Strains and stresses Hong Kong Polytechnic University -- Dissertations |
| Department: | Department of Civil and Environmental Engineering |
| Pages: | vii, 150 pages : color illustrations |
| Language: | English |
| Abstract: | Safe application of steel materials in practice requires quantification of mechanical behaviors of steels at different ranges of deformations. Experimental investigations, such as standard tensile tests, can not only provide load-deformation curves or engineering stress-strain curves of the steel materials, but also the basic mechanical properties, such as yield strengths and tensile strengths, are readily obtained. The engineering stress-strain curves are effective in structural design before an onset of necking in the steel materials. However, after the onset of necking, the engineering stress-strain curves are found to be invalid, and the true stress-strain curve should be adopted. This dissertation presents both the experimental and numerical investigations into the true stress-strain characteristics of S275 and S690 steel materials. Experimental investigations in the form of standard tensile tests with Digital Image Correlation technology provide instantaneous dimensions and deformations of the test coupons with a high degree of precision over a full range of deformations. The numerical investigation is mainly about predicting the load-deformation curves in Abaqus with the true stress-strain curves derived from different methods. These methods are i) Linear Law method, and ii) Power Law method, and iii) Minimum Area Method . It should be noted that the Minimum Area Method is applicable to i) small deformations for which a uniform stress-strain distribution within the cross-section of the steel is assumed, and ii) large deformations for which a non-uniform stress-strain distribution within the cross-section of the steel is assumed. Comparison between different methods is presented, and it is found that the Minimum Area Method can provide the most precise true stress-strain characteristics of the steel coupons at large deformations up to fracture. |
| Rights: | All rights reserved |
| Access: | restricted access |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| 5278.pdf | For All Users (off-campus access for PolyU Staff & Students only) | 9.79 MB | Adobe PDF | View/Open |
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