Download or read book Analytical and Computational Modeling of Temperature dependent Material Properties Residual Stress and Torsional Behavior for Cold formed Steel Members written by Yu Xia (Ph.D.) and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thin-walled cold-formed steel (CFS) members have been widely used in the construction industry because of their unique advantages. A new family of CFS known as advanced high-strength steel (AHSS) has been developed with unprecedented combinations of strength and ductility. An extensive study of the material properties and member structural performance of AHSS is presented. The study consists of five different parts. The first three parts introduce the material properties of AHSS under different temperature scenarios including ambient, elevated temperatures, and subzero temperatures. Each of the three parts contains the experimental stress-strain curves and key material properties, as well as the developments of the constitutive relation modeling and the predictive equations for the parameters required by the proposed constitutive models. The fourth part introduces the residual stress distribution of press-braked AHSS members. An experimental study using the sectioning method is conducted for the residual stress measurement and a numerical study using a validated finite element model is presented to provide extra residual stress data through the steel sheet thickness. The fifth part introduces the torsional behaviors of CFS members. It contains two parametric studies using validated models. The first parametric study contains the predictive equations of bimoment capacity for members under torsional loads. The second parametric study contains the controlling interaction equations between moment and bimoment for members under combined bending-torsion with different bracing and loading conditions. The study shows the uniqueness of AHSS material and structural behaviors compared with conventional steel and provides useful data and information for potential AHSS applications in the construction industry in the future.
Download or read book Cold formed Steel Behavior and Design written by Benjamin William Schafer and published by . This book was released on 1997 with total page 976 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Computational Model of Cold formed Steel Members written by Hamed Amouzegar and published by . This book was released on 2016 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt: Post-buckling behavior of thin-walled, cold-formed steel members is complicated.The discrepancy between the experimentally measured load-deformation curves and computational simulations stems from a fundamental lack of knowledge about the initial stage of these members, such as residual stresses and strains and geometric imperfections. We develop a numerical algorithm to calculate the through-thickness variation of residual stresses and strains. The algorithm calculates the stresses and strains by viewing the manufacturing process as a combination of elasto-plastic bending and spring back in a wide plate under plane strain conditions. The results obtained via the proposed algorithm are verified with the available closed formed solutions,finite element analysis results and experimental measurements. A parametric study is performed to evaluate the effect of the coil radius and cross-sectional and material properties on the residual stresses and strains. We also propose a framework for statistical analysis of the impact of global imperfection modes on collapse behavior of cold-formed steel members. The measured global geometric imperfections of cold-formed lipped channels are used within a stochastic fully nonlinear simulation framework to calculate an ensemble of load-deformation curves as well as load carrying capacities describing, in a statistical sense, the collapse behavior of cold-formed lipped channels. A robust analysis of variance (ANOVA) technique is finally used to examine the contribution of different imperfection modes in the variability present in the nonlinear response and to make quantitative conclusions on the impact of imperfect ion modes, both individually and in groups, on the collapse behavior.
Download or read book Handbook of Residual Stress and Deformation of Steel written by George E. Totten and published by ASM International. This book was released on 2002 with total page 496 pages. Available in PDF, EPUB and Kindle. Book excerpt: Annotation Examines the factors that contribute to overall steel deformation problems. The 27 articles address the effect of materials and processing, the measurement and prediction of residual stress and distortion, and residual stress formation in the shaping of materials, during hardening processes, and during manufacturing processes. Some of the topics are the stability and relaxation behavior of macro and micro residual stresses, stress determination in coatings, the effects of process equipment design, the application of metallo- thermo-mechanic to quenching, inducing compressive stresses through controlled shot peening, and the origin and assessment of residual stresses during welding and brazing. Annotation c. Book News, Inc., Portland, OR (booknews.com)
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1977 with total page 1006 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Structural Behavior of Cold formed Steel Members Made of Thick Sheets and Plates written by Ai-Shen Liu and published by . This book was released on 1974 with total page 548 pages. Available in PDF, EPUB and Kindle. Book excerpt: "It is well-known that the current AlSI Specification for the design of cold-formed steel structural members has been developed mainly for thin steel sections. In order to extend the applicability of the specification for the design of cold-formed steel members thicker than 1/4 in., both analytical and experimental investigations have recently been conducted with special emphases on the effects of cold work on the mechanical properties of corners and the strength of bolted connections. For the effects of cold work, previous investigations have shown that the phenomena of strain hardening and strain aging are main factors which affect the mechanical properties of corners. The yield point and ultimate tensile strength of corners are larger than those in virgin steels, and the ductility of virgin steels will be decreased as a corner is formed. Mathematical corner models developed by other investigators for the prediction of tensile yield points of corners were studied in detail. It was found that the increase in yield point of corners is dependent upon the ratio of virgin ultimate tensile strength to virgin tensile yield point, the ratio of inside bend radius to the thickness of the corner, and the virgin tensile yield point. In order to study the possible effects of thickness on the mechanical properties of corners, a total of one hundred corner tests have been conducted. The corner specimens used in the test program were cold-formed from 1/2 in. and 1 in. thick A36 and A588 steel plates with R/t ratios of 3, 5 and 6. On the basis of the test data obtained from the recent study and previous investigations, it was found that in addition to the above-mentioned three factors, the increase in yield point of corners also depends on the type of stress-strain curves of virgin steels, but is not directly affected by the thickness of corners. Consequently, modified equations were derived on the basis of a regression analysis which can be alternatively used for the determination of tensile yield point of corners, when the virgin steel has a sharp yielding type of stress-strain curve with a large plateau. In view of the fact that sharp yielding type of stress-strain curves is usually found for hot-rolled steels, and gradual yielding type of stress-strain curves is found for cold-reduced steels, the current AISI formulas can be used for cold-reduced steels and other steels having a sharp yielding type of stress-strain curve with a small plateau. It has been realized that the AISC Specification is primarily developed for the design of thick, hot-rolled steel members. Studies of the strength of bolted connections made of thick, cold-formed steel members were, thus, conducted mainly by comparing the AISI and AISC Specifications. Other specifications, recommendations, and standards being used abroad and the research work carried out at other universities were also reviewed and considered. From a study of design criteria for bolted connections listed in various specifications, it was found that the main difference for the design of bolted connections made of thin and thick steels is the allowable bearing stress and the related, required edge distance in line of stress. In order to study further the bearing capacity of bolted connections, a total of thirty single-shear and double-shear bolted connections were tested. The test specimens were fabricated from A36 and A570 steels with thicknesses of 11 ga., 3/16 in., and 1/4 in. From a thorough analysis of the available results of connection tests, two modified design equations were derived for the determination of the minimum edge distance in line of stress and allowable bearing stress using ordinary bolts. These modified equations not only apply to steels with various ductilities, but also close the gap between the AISI and AISC Specifications for allowable bearing stress. These equations also provide a conservative basis for the design of bolted connections using high-strength bolts. For purposes of design, simplified equations were also developed and recommended for the minimum edge distance and allowable bearing stress. With regard to other design requirements for bolted connections, such as allowable tension stress on net section and allowable shear stress on bolts, the current AISI design criteria can also be used for connections made of thick, cold-formed steel members "--Abstract, pages ii-iv.
Download or read book Applied mechanics reviews written by and published by . This book was released on 1948 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book CIM Bulletin written by Canadian Institute of Mining and Metallurgy and published by . This book was released on 1993 with total page 1158 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Metals Abstracts written by and published by . This book was released on 1998 with total page 1076 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Temperature dependent Material Modeling for Structural Steels written by Mina Seif and published by . This book was released on 2016 with total page 145 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report presents the formulation and application of a newly developed temperature-dependent material model for structural steels. First it presents a model for computing the stress-strain behavior of structural steel for conditions appropriate to fire. The model accounts for the change in yield strength with temperature, the change in the amount of post-yield strain hardening with both temperature and room-temperature yield strength, and the change in strength with increasing strain rate. Then, this NIST stress-strain model is used for predicting flexural buckling of steel columns subjected to elevated temperature. The main focus of this part of the study is to evaluate the applicability of the NIST model for predicting the behavior of steel gravity columns at elevated temperatures using the finite-element method. Besides the stress-strain behavior, another key issue in evaluating the response of structural systems to fire effects is the modeling of fracture, which is required to capture failure modes such as tear out in connection plates and bolt shear. Fracture can be simulated in explicit finite element analysis using element erosion, in which elements are removed from the analysis when specified failure criteria are satisfied. A finite element material modeling methodology is presented for structural steels and bolts at elevated temperatures that incorporates erosion-based modeling of fracture. The failure criterion was calibrated against high- temperature experimental data on elongation of tensile coupons at fracture, and its dependence on temperature and mesh size was investigated. Finally, these temperature-dependent material models for structural steel and bolts that incorporate erosion-based modeling of fracture were implemented to study the performance of steel moment frame assemblies at elevated temperatures.
Download or read book CIM Bulletin written by Canadian Institute of Mining, Metallurgy and Petroleum and published by . This book was released on 1993 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Structural Behavior of Cold formed Steel Members with Perforated Elements written by Charles S. Davis and published by . This book was released on 1972 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Analytical and experimental investigations have been conducted to study the influence of perforations on the structural behavior of cold-formed steel structural members. Since in many cases, the load-carrying capacity of cold-formed steel members depends on the buckling behavior of individual component elements, emphasis has been concentrated on the study of the instability and post-buckling strength of perforated elements. In this investigation, the buckling loads and post-buckling strength of stiffened and unstiffened compression elements having single circular and square holes have been studied analytically by using the finite element method. The effects of different holes on the buckling coefficient have been verified by the experimental data obtained from the testing of columns and beams with perforated flanges. The equations for determination of the effective width have been developed on the basis of the post-buckling strength of compression elements. An experimental investigation has been conducted to study the influence of holes on the shear buckling load of beam webs. The test data was compared with analytical results of other investigators. Better correlation was found between the test data and the analytical solution for the simple support condition. A load reduction equation was derived on the basis of the experimental study. The crippling strength of perforated webs were also investigated experimentally. In this investigation, twenty tests were conducted to cover a practical range of height-to-thickness ratios. Based on the results obtained from tests, load reduction factors were derived for steel members with circular and square perforated webs. The stability of perforated plates subjected to equal and opposite point loads were investigated. The trend of this analytic study was found in agreement with the experimental investigation. Design recommendations are developed for: perforated stiffened compression elements, perforated unstiffened compression elements, perforated shear webs, and crippling of perforated webs"--Abstract, pages ii-iii.
Download or read book Residual Stresses in Cold formed Steel Sections and Their Effect on Column Behaviour written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: PolyU Library Call No.: [THS] LG51 .H577P CSE 2005 Quach.
Download or read book Residual Stresses in Cold formed Steel Sections and Their Effect on Column Behaviour written by Wai Meng Quach and published by . This book was released on 2005 with total page 900 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Numerical Studies of Residual Stress in Cold Formed Steel Sigma Sections written by Feiliang Wang and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental and Analytical Investigation of Optimized Cold formed Steel Compression Members written by Daniel John Klingshirn and published by . This book was released on 2009 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: Keywords: cold-formed steel, Direct Strength Method, optimized sections, sigma section.
Download or read book Metals Abstracts Index written by and published by . This book was released on 1996 with total page 1622 pages. Available in PDF, EPUB and Kindle. Book excerpt:
