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This paper aims to present an investigation conducted to evaluate the effects of important parameters affecting the structural fire performance of light gauge steel frame (LSF) walls. It also evaluates the applicability of commonly used critical hot flange temperature method to determine the fire resistance ratings (FRR) of different LSF walls.

The effects of important parameters such as stud section profiles and their dimensions, elevated temperature mechanical property reduction factors of the steel used, types of wall configurations and fire curves on the FRR of LSF walls were investigated. An extensive finite element analysis-based parametric study was conducted to evaluate their effects (finite element analysis – FEA). For this purpose, finite element models which were validated using the full-scale fire test results were used. Using the structural capacities obtained from FEAs, the load ratio versus FRR curves were produced for all the different LSF walls considered.

Stud depth and thickness significantly affected the fire performance of LSF walls because of the differences in temperature development pattern, thermal bowing deflections and the failure modes of stud. The FRR of LSF walls increased significantly when steel studs with higher elevated temperature mechanical property reduction factors were used. FRR significantly changed when realistic design fire curves were used instead of the standard fire curve. Furthermore, both the critical hot and average flange temperature methods were found to be unsuitable to predict the FRR of LSF walls.

The developed comprehensive fire performance data would facilitate the development of LSF walls with enhanced fire performance, and, importantly, it would facilitate and advance the successful applications of hollow flange channel section studs in LSF walls.

This research was aimed at investigating the fire performance of LSF wall systems by using 3-D heat transfer FE models of existing LSF wall system configurations.

This research was focused on investigating the fire performance of LSF wall systems by using 3-D heat transfer finite element models of existing LSF wall system configurations. The analysis results were validated by using the available fire test results of five different LSF wall configurations.

The validated finite element models were used to conduct a parametric study on a range of non-load bearing and load bearing LSF wall configurations to predict their fire resistance levels (FRLs) for varying load ratios.

Fire performance of LSF wall systems with different configurations can be understood by performing full-scale fire tests. However, these full-scale fire tests are time consuming, labour intensive and expensive. On the other hand, finite element analysis (FEA) provides a simple method of investigating the fire performance of LSF wall systems to understand their thermal-mechanical behaviour. Recent numerical research studies have focused on investigating the fire performances of LSF wall systems by using finite element (FE) models. Most of these FE models were developed based on 2-D FE platform capable of performing either heat transfer or structural analysis separately. Therefore, this paper presents the details of a 3-D FEA methodology to develop the capabilities to perform fully-coupled thermal-mechanical analyses of LSF walls exposed to fire in future.

Prefabricated extruded hollow-core slabs are preferred building components for floor structures in several countries. It is therefore important to be able to document the fire resistance of these slabs proving fulfilment of standard fire resistance requirements of 60 and 120 min found in most national building regulations. The paper aims to present a detailed analysis of the mechanisms responsible for the loss of load-bearing capacity of hollow-core slabs when exposed to fire.

Furthermore, it compares theoretical calculation and assessment according to the structural codes with data derived from a standard fire test and from a thorough examination of the comprehensive test documentation available on fire exposed hollow-core slabs.

Mechanisms for loss of load-bearing capacity are clarified, and evidence of the fire resistance is found.

For the first time, the mechanisms responsible for loss of load-bearing capacity are identified, and test results and calculation approach are for the first time applied in accordance with each other for assessment of fire resistance of the structure.

Skin‐stressed aircraft bodies, hulls, or floats comprise a shell composed of a number of channel section strips assembled in sets with the channel flanges projecting inwardly, each set constituting a section of the skin and connected to the adjacent set by securing together outwardly directed flanges formed on or fixed to the marginal strips of the sets. A monocoque fuselage 1, Fig. 1, of substantially oval section tapering in width to the rear end 5 and provided with an engine supporting frame at the forward end, is divided at 10 into two parts, of which the forward is built up in two sections 22, 23 joined in a horizontal plane 24 and the after part is built up from sections 2, 3, Fig. 3, joined in the plane of symmetry. The latter sections each comprise a half‐bulkhead 2a, 3a respectively to which channel strips 6 are secured by engagement of side flanges 6a in peripheral slots 7 and by welding. The abutting flanges 6a of the several strips are additionally interconnected by riveting along their length. The half‐bulkheads together with their attached channel strips are interconnected by engagement of a rod 9 in tubular lugs 8 formed alternately on the edges of the parts 2a, 3a, and also by riveting or bolting together the marginal pairs of channel strips. These may be formed with up‐turned abutting flanges 11 which are faired by a split tube 13 slidden or otherwise engaged therewith. Adjacent fuselage parts may be interconnected by riveting or otherwise securing juxtaposed bulk‐heads. The channel strips 6 are shaped to correspond with the longitudinal changes in section of the fuselage and may be reduced in gauge toward the tail or be of varying gauge to suit localized stresses. In a modification in which annular frames 16 of channel or box‐section are substituted for bulk‐heads, Fig. 10, the flanges 6a of channels 6 are inwardly bent at 6b to rest on the frames and attachment is by angle members 17, of which one limb is secured to flanges 6a and one to a side wall of frame 16. Fig. 11 shows modified channel member, the flanges of which form on assembly a series of longitudinal stiffeners, 6c. Attachment to frame 16 is by bent‐up fittings 22 secured to the flanges by bolts 24 which connect them together.

The purpose of this paper is to focus on the influences of residual stresses which were induced during roll-forming sections on lateral-torsional buckling of thin-walled cold-formed steel channel and built-up I-sections beams. Built-up I section is made up of two back-to-back cold-formed channel beams. In this direction, at the primary stage, the roll-forming process of a channel section was simulated in ABAQUS environment and the accuracy of the result was verified with those existing experiments. Residual stresses and strains in both longitudinal and circumferential transverse directions were extracted and considered in the lateral-torsional buckling analysis under uniform end moments. The contribution of the current research is devoted to the numerical simulation of the rolling process in ABAQUS software enabling to restore the remaining stresses and strains for the buckling analysis in the identical software. The results showed that the residual stresses decrease considerably the lateral-torsional buckling strength as they have a major impact on short-span beams for channel sections and larger span for built-up I sections. The obtained moment capacity from the buckling analysis was compared to the predictions by American Iron and Steel Institute design code and it is found to be conservative.

This paper has explained a numerical study on the roll-forming process of a channel section and member moment capacities related to the lateral-torsional buckling of the rolled form channel and built-up I-sections beams under uniform bending about its major axis. It has also investigated the effects of residual stresses and strains on the behaviour of this buckling mode.

The residuals decrease the moment capacities of the channel beams and have major effect on shorter spans and also increase the local buckling strength of compression flange. But the residuals have major effect on larger spans for built-up I sections. It could be seen that the ratio of moment (with residuals and without residuals) for singly symmetric sections is more pronounced than doubly symmetric sections. So it is recommended to use doubly symmetric section of cold-formed section beams.

The incorporation of residual stresses and strains in the process of numerical simulation of rolled forming of cold-formed steel sections under end moments is the main contribution of the current work. The effect of residual stresses and strains on the lateral-torsional buckling is, for the first time, addressed in the paper.

Each rib of an aircraft wing comprising upper and lower flanges connected by inclined bracing is connected to each spar at one place only. A metal wing is shown in which shaped channel members 26, 27 of the ribs are connected together by shear bracing 28, 29 certain of the members 28 being connected to gusset plates 33 secured to the centres of vertical struts 16 of the spars which have no other connections to the ribs. The metal covering of the wing is connected to the spars through wooden blocks 35, Fig. 5, secured to the flanges of the spars by wood screws passed through hollow rivets 37. Alternatively the blocks 35 may be secured to the spars by long hollow rivets 38, Fig. 6, which alternate with short rivets 37, strips of plywood 39 being inserted under the rivet heads. The spar is constructed as described in Specification 367,048, or it may have shear bracing comprising a lattice work of channel members crossing one another back to back.

Although the actual residual stress distribution in any structural steel member can be only obtained by experimental measurements, it is known to be a difficult, tedious and inefficient piece of work with limited accuracy. Thus, besides aiming at clarifying structural designers and researchers about the possible ways of modelling residual stresses when performing finite element analysis (FEA), the purpose of this paper is to provide an effective literature review of the longitudinal membrane residual stress analytical expressions for carbon steel non-heavy sections, covering a vast range of structural shapes (plates, I, H, L, T, cruciform, SHS, RHS and LSB) and fabrication processes (hot-rolling, welding and cold-forming).

This is a literature review.

Those residual stresses are those often required as input of numerical analyses, since the other types are approximately accounted for through the s-e curves of coupons cut from member walls.

One of the most challenging aspects in FEA aimed to simulate the real behaviour of steel members, is the modelling of residual stresses.

Besides aiming at clarifying structural designers and researchers about the possible ways of modelling residual stresses when performing FEA, this paper also provides an effective literature review of the longitudinal membrane residual stress analytical expressions for carbon steel non-heavy sections, covering a vast range of structural shapes (plates, I, H, L, T, cruciform, SHS, RHS and LSB) and fabrication processes (hot-rolling, welding and cold-forming).

THE following is a brief account of how Monospar machines are being made, rather than a description of a completely worked‐out production system, and also of the considerations which were borne in mind while the machine was being designed. These considerations can be grouped under three headings: Design, Production and Maintenance, and will be dealt with after a brief description of the whole machine, which may be of assistance in visualising how the components to be described are combined.

IT is a comparatively simple matter to settle down to the quantity production of an aeroplane in a brand new factory where expense is no object when considering the purchase of new machines and the ordering of tools, but it is far different when the factory already exists and has to be adapted to produce a much greater number of machines than had ever been contemplated by its original constructors and when the cost of the original design has to be added to that of tooling and overheads. The production of the Hawker Hurricane 1 affords a striking example of the successful solution of this problem. No one with any knowledge of the Kingston works can do anything but admit that they are not ideal. The buildings are old and at no time has work been slack enough to permit the closing of any one section for its complete rebuilding. Another handicapping feature was the lack of space in the immediate vicinity to allow for expansion. It is these facts that must be understood and appreciated for the true realisation of the work described in the following pages.

In this work, a numerical algorithm is presented for stability analysis of cold-formed steel (CFS) channel sections.

A nonlinear optimization problem is formulated using energy-based technique of idealized channel section subject shear, compression and biaxial bending. The total potential energy is minimized with respect to skew angle and half wavelength of the buckling mode. The optimization algorithm is updated sequentially using quadratic approximation until minimum buckling coefficient is attained. The developed algorithm is validated using other numerical techniques.

The described algorithm is computationally effective and can be utilized in the industry for analysis of CFS channels under any load combination.

The paper offers a new tool for engineers in practice to analyze channels subject to combined loadings.

Very limited literature dealt with the stability of channels under combined loading. A new numerical algorithm is provided to practitioners to utilize in the industry for analysis of channel sections under combined loading. Unlike finite element or finite strip methods, the channel is not discretized into subelements. Mathematical programming technique is used to find the buckling load. Parametric studies are then carried out to highlight influences of geometric interaction of the channel components and to provide useful guidance to the design of CFS channels.