జర్నల్ ఆఫ్ స్టీల్ స్ట్రక్చర్స్ & కన్స్ట్రక్షన్

Cold-formed steel flexural members can experience buckling failure at the web when compressive loads are applied to the flanges. Determining the web crippling strength analytically can be difficult because it depends on various parameters including loading conditions, bearing length, thickness of the material, web inclination, flange lengths etc. Due to these parameters, the current design method was developed based on the experimental data only. The paper presents an attempt to develop a semi-analytical design approach for the web crippling strength using the Direct Strength Method concept. The focus is on the cold-formed steel C and Z sections subjected to onflange loading conditions. The research indicates that the Direct Strength Method is appropriate for predicting the web crippling strength. New design equations are proposed and verified by with the experimental results.

Cold-formed steel flexural members can experience buckling failure at the web when compressive loads are applied to the flanges. Determining the web crippling strength analytically can be difficult because it depends on various parameters including loading conditions, bearing length, thickness of the material, web inclination, flange lengths etc. Due to these parameters, the current design method was developed based on the experimental data only. The paper presents an attempt to develop a semi-analytical design approach for the web crippling strength using the Direct Strength Method concept. The focus is on the cold-formed steel C and Z sections subjected to onflange loading conditions. The research indicates that the Direct Strength Method is appropriate for predicting the web crippling strength. New design equations are proposed and verified by with the experimental results.

Seismic retrofitting of existing reinforced concrete (RC) buildings, designed in the last decades in seismic areas, is one of the most complex tasks for structural engineers: in fact, it includes several issues, such as quantifying the capacity of existing members, designing the supplemental ones and analysing the whole structure. This paper is intended as a contribution to clarifying some of those issues. First of all, a model based on using 1D finite elements with fiber section discretization is proposed for simulating the behaviour of a cost-competitive steel device that can be employed as a link in Y-shaped eccentric bracings (EB): particularly, the cyclic response and the low-cycle fatigue degradation is modelled, based on the results of obtained in a previous experimental research carried out at the University of Salerno. Secondly, the global response of an existing RC frame equipped with the aforementioned devices is investigated via Non Linear Time History (NLTH) analyses. Taking into account the lowcycle fatigue often leads to significantly more severe seismic displacement demand value on the retrofitted structure: a close correlation is unveiled between some specific features of the seismic signals adopted in the NLTH and the actual influence of low-cycle fatigue.

Ferrocement is a composite material consisting of layered wire meshes and rich cement-sand mortar which imparts high degree of ductility and energy absorbing capacity. Although ferrocement has proven itself as an excellent material for low cost housing, its durability continues to be a matter of concern owing to the corrosion susceptibility of the small diameter metallic wire meshes. Protection of reinforcement in ferrocement is usually achieved through the galvanized wire mesh, increased effective cover and dense mortar. These methods give only partial protection to the reinforcement against corrosion. This article reviews the studies undertaken to control corrosion in the ferrocement composites and thereby improving the durability of the composites.z

Poland is one of the most important producers of raw steel and steel products in Europe. During the past decade a considerable number of companies in steel sector in Poland efforts to reduce their impact on the environment, applying the principles of cleaner production (CP). The restructuring of the industry and implementation new eco-technologies caused an increase in share of material recycling, including steel scrap recovered in production processes and from post-use recycling. Depending on the type of steel waste, it can be returned to the process as energy source or raw material for steel fabrication or else be traded as co-product to other industrial applications. The reuse of these products is of great importance for the sector owing to economical and environmental aspects Such directions of steel waste utilization are consistent with the ‘zero waste’ strategy and they should be further investigated in Polish conditions, taking into account the possibilities of development, modernization and construction of new installations. These eco-technologies will be especially supported by European funds in new programming period 2014-2020.

Structural response under seismic loadings is typically nonlinear and related to many factors, such as structural configurations, material properties, occupancy loads, earthquake hazards and incomplete knowledge of the system. As all these factors have their sources of uncertainties, structural response under seismic loading has its probabilistic nature. Therefore, the random variable for any structural demand follows a multivariate probability distribution over the integration domain defined by the limit states. Examining the probabilistic behaviour of structures under earthquake loadings has to consider the sources of uncertainties from all factors. It is also known that numerical methods, such as the finite element method, are commonly used to predict nonlinear structural response. The probabilistic structural demand is a discrete probability function of its related variables. In order to examine seismic risks and mitigate potential damages to structures, it is important to accurately quantify seismic reliability of structures. The traditional seismic reliability analysis uses approximate algebra equations with parameters obtained from aggregation of data points of dynamic analysis, which may not be able to produce accurate results. In this paper, probabilistic seismic demands are solved with numerical procedures of the traditional SAC method and the Monte Carlo simulation. These methods rely on the results from repeatable nonlinear dynamic analyses, which were traditionally considered to be a bottle-neck due to limited computing resources. The recent progress in parallel computing technology and open-source software has made such scientific computation affordable for the engineering community. Two parallel computer systems were used to analyze seismic reliability of the structures. One system is based on multiple personal computers in typical computer labs. The other system is to use high performance computer clusters. Both systems were applied to analyze a two–storey wood frame building and a three-storey steel moment building, respectively