Author
Mahmud Ashraf
Other affiliations: Nanjing Forestry University, Australian Defence Force Academy, Imperial College London ...read more
Bio: Mahmud Ashraf is an academic researcher from Deakin University. The author has contributed to research in topics: Materials science & Composite material. The author has an hindex of 22, co-authored 114 publications receiving 1944 citations. Previous affiliations of Mahmud Ashraf include Nanjing Forestry University & Australian Defence Force Academy.
Papers published on a yearly basis
Papers
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TL;DR: In this paper, an overview of manufacturing and processing of microlattices with corresponding mechanical properties is presented, as well as possible future uses of micro lattices and demonstrated use of cellular materials analogous to applications of micro-attices are also explored.
279 citations
TL;DR: In this article, a more accurate material model and a continuous measure of cross-section deformation capacity were proposed to provide more rational and efficient designs for structural carbon steel sections, and the proposed method offers average increases in member resistances of around 20% over the current Eurocode approach, and a reduction in scatter of the prediction.
274 citations
TL;DR: In this paper, the authors present an overview and reappraisal of previous pertinent research, together with an evaluation of existing elevated temperature stainless steel stress-strain test data and previously proposed material models.
195 citations
TL;DR: In this article, the authors investigated all important aspects for modelling stainless steel cross-sections through carefully designed parametric studies, and compared the numerically obtained load-deformation responses with selected experimental results.
Abstract: Stainless steel's characteristic nonlinear, rounded stress–strain behaviour requires accurate recognition in numerical modelling. Its response to cold-working is far more pronounced than that of ordinary carbon steel and hence appropriate modelling of the cold-worked corner regions is very important. Despite the importance of geometrical imperfections, their measurement is not a very common practice and assumed models are generally adopted in numerical investigations—often without proper verification. This paper investigates all important aspects for modelling stainless steel cross-sections through carefully designed parametric studies. Different cross-section types have been considered and the numerically obtained load–deformation responses have been compared with selected experimental results; the findings form the basis for specific guidelines. These proposals have been verified by application to all available stainless steel stub column tests obtained from different sources. The predicted numerical results have shown excellent agreement with those obtained experimentally.
155 citations
TL;DR: In this paper, a method for predicting the enhanced strength of the corner regions of cold-formed stainless steel sections is presented, where all available test results are collected and used to devise generalised models to predict strength enhancements for different cold-forming processes.
116 citations
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TL;DR: In this article, the authors provide values and predictive expressions for the key parameters in existing stainless steel material models based on the analysis of a comprehensive experimental database, which comprises experimental stress-strain curves collected from the literature, supplemented by some tensile tests on austenitic, ferritic and duplex stainless steel coupons conducted herein.
341 citations
TL;DR: The use of stainless steel as a structural material has been extensively studied in the literature as mentioned in this paper, with a focus on the structural design of structural stainless steel structures and its application in conventional structures.
Abstract: The past 15 years have seen the introduction or major revision of structural stainless steel design codes throughout the world, and at the same time, interest in the use of stainless steel in construction has been accelerating. Historically the high initial material cost of stainless steel has limited its use primarily to specialist and prestige applications. However, the emergence of design codes, a better awareness of the additional benefits of stainless steel and a transition towards sustainability are bringing more widespread use into conventional structures. Although a number of similarities between stainless steel and ordinary carbon steel exist, there is sufficient diversity in their physical properties to require separate treatment in structural design. In addition to the straightforward differences in basic material properties (such as Young's modulus and yield strength), further fundamental differences exist, such as the nature of the stress–strain curve and the material's response to cold-work and elevated temperatures; these have implications at ultimate, serviceability and fire limit states. This paper describes the use of stainless steel as a structural material, discusses current structural design provisions, reviews recent research activities and highlights the important findings and developments.
336 citations
TL;DR: In this paper, a series of tests were carried out on short and slender concrete-filled stainless steel tubular columns to explore their performance under axial compression or combined actions of axial force and bending moment.
311 citations
TL;DR: In this paper, the authors investigated the mechanical properties and energy absorption abilities of three types of TPMS sheet structures (Primitive, Diamond, and Gyroid) fabricated by selective laser melting (SLM) with 316 L stainless steel under compression loading and classified their failure mechanisms and printing accuracy with the help of numerical analysis.
Abstract: Designing metallic cellular structures with triply periodic minimal surface (TPMS) sheet cores is a novel approach for lightweight and multi-functional structural applications. Different from current honeycombs and lattices, TPMS sheet structures are composed of continuous and smooth shells, allowing for large surface areas and continuous internal channels. In this paper, we investigate the mechanical properties and energy absorption abilities of three types of TPMS sheet structures (Primitive, Diamond, and Gyroid) fabricated by selective laser melting (SLM) with 316 L stainless steel under compression loading and classify their failure mechanisms and printing accuracy with the help of numerical analysis. Experimental results reveal the superior stiffness, plateau stress and energy absorption ability of TPMS sheet structures compared to body-centred cubic lattices, with Diamond-type sheet structures performing best. Nonlinear finite element simulation results also show that Diamond and Gyroid sheet structures display relatively uniform stress distributions across all lattice cells under compression, leading to stable collapse mechanisms and desired energy absorption performance. In contrast, Primitive-type structures display rapid diagonal shear band development followed by localized wall buckling. Lastly, an energy absorption diagram is developed to facilitate a systematic way to select optimal densities of TPMS structures for energy absorbing applications.
309 citations
TL;DR: In this article, a more accurate material model and a continuous measure of cross-section deformation capacity were proposed to provide more rational and efficient designs for structural carbon steel sections, and the proposed method offers average increases in member resistances of around 20% over the current Eurocode approach, and a reduction in scatter of the prediction.
274 citations