[en] Mechanical properties of stainless-clad (SC) steel plates at elevated temperatures are key parameters for fire resistant design and numerical simulation analysis of SC steel structures. Compared with pure stainless steel and pure ordinary steel, SC steel not only combines advantages of the two component metals, but may also balance the performance and cost; however, it behaves quite differently in terms of material properties. In order to quantify this performance, tension coupon tests at room as well as elevated temperatures are conducted on the SC steel plate. Based on the test results, failure modes of the tension coupons are analysed, and full-range stress-strain curves are obtained; material properties are accordingly determined and described herein, and analyses are performed on several properties including yield strength, ultimate tensile stress, elastic modulus and elongation after fracture. It is found that with an increase of the temperature, both the elastic modulus and strengths are reduced remarkably. For determining these material properties quantitatively and developing robust constitutive models of the SC steel at elevated temperatures, more test data are needed, and the incorporation of the effects of the clad ratio on the material properties at both room and elevated temperatures is also necessary. The present research outcomes may provide valuable reference for fire design and calculations of the SC steel. (Author)

[en] Clad steel possesses benefits of the both component metals in terms of mechanical performance, corrosion resistance, sustainability and lower full lifecycle cost, etc. As a result, it has been more and more widely used in the petroleum, chemical, marine, shipbuilding and metallurgical industries, including stainless-clad steel and titanium clad steel. Such clad steel has also great potential for application in building and bridge structures. For better understanding material properties of such clad steel, a review of research progress available in the literature is conducted herein, as well as recent research undertaken by the authors’ group at Tsinghua University. It can be found that very limited research reported in the literature mainly concerns static material properties of the clad steel, and primary relations between clad ratio and strength are suggested. The authors carried out material tests on both titanium and stainless-clad steel plates, with different clad ratios being incorporated. For the stainless-clad steel tests, both material and butt welded connections are tested, and various elevated temperatures are considered. In addition, tension coupon tests under cyclic loadings are also briefly introduced herein. Primary constitutive relations developed by the authors are reviewed in this paper. All the research findings and proposed formulae may provide an essential basis for future structural analysis, and may promote its application in structural engineering. (Author)

[en] In the 1980’s Manchester University carried out over 110 tests on cylinders with a composite wall (steel-concrete-steel) subjected to external pressure as already reported in the literature. This paper describes further tests on 9 cylinders with a composite wall and a dome end subjected to external pressure and reports the results and compares them with theory. The cylinders were 500 mm diameter and 1250 mm long and four of them had penetrations through the cylinder wall. These tests were carried out under contract for Tecnomare SpA of Italy and have not been previously reported because of confidentiality reasons. The agreement between test behaviour, failure load and the theory developed at Manchester University is good. The philosophy for the design of such vessels for seabed structures is discussed and a ‘depth margin’ method proposed as it is a more realistic way of applying safety. Examples of designs for different depths are given and compared with the predicted failure pressure. (Author)