A Restoring Force Model for Prefabricated Concrete Shear Walls with Built-In Steel Sections

Prefabricated shear walls have been widely used in engineering structures. Vertical connection joints of the walls are the key to ensure the safety of the structures. Steel–concrete composite structures have been proved to have a good bearing capacity and ductility. In this paper, a new type of prefabricated structure is proposed, in which vertical wall members are connected together through built-in steel sections and cast-in-place concrete. This paper studies the seismic performance of the proposed prefabricated concrete shear wall structure. Hysteretic curves and skeleton curves of the shear wall are obtained based on experimental analyses. A dimensionless skeleton curve model is developed using the theory of material mechanics and the method of regression analysis. A stiffness calculation method for different loading stages is obtained and a restoring force model is proposed. The proposed innovative prefabricated shear wall structure provides good resistance to seismic performance and the related analysis provides a fundamental reference for studies of prefabricated shear wall structures.

Investigations of the through-thickness residual stress distribution during the partial heating roll forming process of square and rectangular hollow steel sections

With the growing demand for rectangular and square hollow steel sections in the last few decades, the cold roll forming process has become a widely acknowledged hollow sections manufacturing method; however, residual stress generated during the roll forming process is one of the primary concerns on roll-formed products. In this regard, several researchers have conducted numerical and experimental investigations of residual stress distributions on roll-formed steel sections. However, most of the studies found in the literature have been confined to the measurement of residual surface stresses. On the other hand, experimental studies conducted on fatigue and load-carrying capacity of hollow structural steels have shown that there is indeed a simple relation between the through-thickness residual stress distributions and mechanical properties of structures. Thus, this paper employed a proper numerical modelling procedure using LS-DYNA’s finite element code to explore through-thickness residual stress distributions generated during the roll forming process of rectangular and square hollow steel sections from different material grades. Moreover, a small-scale parametric study was conducted to explore the effects of the partial heating roll forming method on through-the-thickness residual stress distributions to satisfy the growing demand for residual stress-free roll-formed products.

Design Calculation for A (G +10) Building (Encode Steel)

The proposed steel building at Mumbai consisting of G+10 storeys, has a built-up area of about 165m2. The typical floor height is 3m above GL and the total height of the building above GL is 33m.Withreference to given plan, the architectural drawings and structural drawings showing plan, elevation, sectional views and connection drawings are drawn by using AUTOCAD 2017.Design calculations (Dead Load, Live Load, Wind Load, Seismic Load) are calculated manually-As per IS codes which are mentioned in technical details. The rolled steel sections for beam and column has been chosen from IS 12778:2004. High tensile steel grade-E350BR has been used for steel sections. And, the analysis of structure is done by using STAAD.Pro V8i SS5.Design of beam and column are manually calculated-As per IS: 800-2007. And, spread sheet has been created to check the beam and column, whether it is safe or not. The connection designs are calculated-As per IS codes by using Welding-As per IS 9595-1996 and Fasteners-As per IS 3757-1985. Bracings are provided in the ground floor between the column to avoid soft storey failure. The material requirements are mentioned based on the design calculations. The total estimation of the building is 1.11cr.

Load bearing capacity of thin-walled rectangular and I-shaped steel sections of short both empty and concrete-filled columns

In this experimental work, strength results obtained on short columns subjected to concentric loads are presented. The specimens used in the tests have made of cold-rolled, thin-walled steel. Twenty short columns of the same cross-section area and wall thickness have been tested as follows: 8 empty and 12 filled with ordinary concrete. In the aim to determine the column section geometry with the highest resistance, three different types of cross-sections have been compared: rectangular, I-shaped unreinforced and, reinforced with 100 mm spaced transversal links. The parameters studied are the specimen height and the cross-sectional steel geometry. The registered experimental results have been compared to the ultimate loads intended by Eurocode 3 for empty columns and by Eurocode 4 for compound columns. These results showed that a concrete-filled composite column had improved strength compared to the empty case. Among the three cross-section types, it has been found that I-section reinforced is the most resistant than the other two sections. Moreover, the load capacity and mode of failure have been influenced by the height of the column. Also, it had noted that the experimental strengths of the tested columns don’t agree well with the EC3 and EC4 results.