Material response and local stability of high-chromium stainless steel welded I-sections

To save material, the safety factor of pressure vessel design standards is gradually decreased from 5.0 to 2.4 in ASME Boiler and Pressure Vessel Codes. So the design methods of pressure vessel should be more rationalized. Considering effects of material strain hardening and non-linear structural deformation, the elastic-plastic stress analysis is the most suitable for pressure vessels design at present. This paper is based on elastic-plastic theory and considers material strain hardening and structural deformation effects. Elastic-plastic stress analyses of pressure vessels are summarized. Firstly, expressions of load and structural deformation relationship were introduced for thin-walled cylindrical and spherical vessels under internal pressure. Secondly, the plastic instability for thin-walled cylindrical and spherical vessels under internal pressure were analysed. Thirdly, to prevent pressure vessels from local failure, the ductile fracture strain of materials was discussed.

Stainless steel is gaining increasing usage in the construction industry and tubular members represent the most widely used structural component. Cold-formed square, rectangular and circular hollow sections are readily available in stainless steel, and more recently, oval hollow sections have been introduced. Oval hollow sections are not currently included in structural design codes, neither for carbon steel nor stainless steel. This paper describes recent tests and finite element modelling performed on stainless steel oval hollow sections in compression and bending. A total of six stub column tests, six in-plane bending tests and eight column buckling tests are reported. Tests have been performed about both the major and minor axes. The results of the tests have been analysed and comparisons have been made with the structural performance of hot-rolled carbon steel elliptical hollow sections. Design rules including cross-section slenderness limits and a column buckling curve have been proposed, and progress towards the development of comprehensive design rules for stainless steel oval hollow sections is reported.

Post-fire behaviour and resistances of S690 high strength steel welded I-section stub columns

Local and post-local buckling of fabricated high-strength steel and composite columns

Local buckling behaviour and capacities of Cold-Formed Steel Double-I-Box stub and short column sections

The cold-formed steel (CFS) double-lipped equal-leg angle is widely used in modular container houses and cold-formed steel buildings. To study the buckling behavior and bearing capacity design method of the cold-formed steel (CFS) double-lipped equal-leg angle under axial compression, 24 CFS double-lipped equal-leg angles with different sections and slenderness ratios the axial compression were conducted. The test results showed that the distortional buckling occurs for specimens with a small width-to-thickness ratio and small slenderness ratio. The buckling interactive with distortional and global flexural buckling was observed for the specimens with small width-to-thickness ratios and large slenderness ratios. The specimens with large width-to-thickness ratios and small slenderness ratios showed interactive buckling with local and distortion buckling. The specimens with large width-to-thickness ratios and large slenderness ratio developed interactive buckling with local, distortional, and global flexural buckling. The finite element model established by ABAQUS software was used to simulate and analyze the test. The buckling modes and the load-carrying capacities analyzed by the finite element model agreed with the test results, which showed that the developed finite element model was feasible to analyze the buckling and bearing capacity of the CFS double-lipped equal-leg angles. The experimental results were compared with those calculated by the direct strength method in the North American standard and the effective width method in the Chinese standard. The comparisons indicated that the calculated results are very conservative with maximum value 36% and 51% for direct strength method and effective width method, respectively. The coefficient of variation was 0.276 and 0.397, respectively. Finally, the modified direct strength method and the modified effective width method were proposed based on the experimental results. The comparison on the ultimate strength between test results and calculated results by using the modified method showed a good agreement. The modified method can be as a proposed desigh method for the ultimate strength of the CFS double-lipped equal-leg angles under axial compression.

Element interaction of cold-formed stainless steel cross-sections subjected to major axis bending

Coupled element and structural level optimisation framework for cold-formed steel frames

Tests, numerical study and design of Q1100 ultra-high strength steel welded I-section stub columns

Tests of cold-formed high strength stainless steel compression members

To analyze the bending collapse behavior of an aluminum square tube under the bending moment load, a finite element simulation for the four-point bending test has been performed. Using an aluminum tube beam specimen partly inserted with two steel bars, local buckling deformation near the center of the tube beam was induced. Simulated moment-rotation angle curve obtained during the post-collapse period of the aluminum tube with steel bars were in good agreement with experimental result, which was comparable to the result obtained from Kecman's theory. Using a combination of the four-point bending test and its finite-element simulation, analysis of the local buckling and the bending collapse behavior of an aluminum tube beam could be quantitatively accomplished.

Experimental study on ferritic stainless steel simply supported and continuous beams

B26 - Mechanical piston rod packings

Effect of severe plastic deformation on aging kinetics of precipitation hardening 17–4 stainless steel

Coal is the main energy source for producing electricity and the most commonly used fossil fuel globally. Significant waste is generated at every stage of the life cycle of coal, including mining, processing, and utilisation. Waste materials generated during open-cast coal mining are commonly termed overburden (OB). Because of low calcium oxide (CaO) content, natural binding cannot be anticipated in these wastes. Therefore, the current study aims to assess the effectiveness of cement-treated OB (CTOB) materials in the subbase or base layer of roads, which will address the concerns associated with depleting aggregates and waste disposal. For bound materials, the tensile characteristic is considered as an important parameter. In the present research tensile strength of CTOB mixes has been assessed through indirect tensile strength and four-point bending tests. The cyclic four-point bending and indirect tensile tests have also been conducted under a stress-controlled environment to evaluate the flexural modulus and indirect tensile resilient modulus of CTOB mixes. Additionally, the laboratory flexural fatigue life has been evaluated for CTOB mixes, and stress and strain-dependent flexural fatigue equations have also been proposed.