James B.P. Lim

James B.P. Lim
University of Auckland · Department of Civil and Environmental Engineering

BEng PhD

About

275
Publications
117,124
Reads
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4,177
Citations
Additional affiliations
December 2013 - present
University of Auckland
Position
  • Professor (Associate)

Publications

Publications (275)
Article
Full-text available
This paper presents the results of a full-scale site fire test performed on a cold-formed steel portal frame building with semi-rigid joints. The purpose of the study is to establish a performance-based approach for the design of such structures in fire boundary conditions. In the full-scale site fire test, the building collapsed asymmetrically at...
Article
The behaviour and design of bolted moment-connections between cold-formed steel members, formed by using brackets bolted to the webs of the section, is considered. The particular problem of the moment-capacity of such joints being lower than that of the cold-formed steel sections being connected because of web buckling, caused by the concentration...
Article
The authors have recently described a cold-formed steel portal framing system in which simple bolted moment-connections, formed through brackets, were used for the eaves and apex joints. Such connections, however, cannot be considered as rigid because of localised in-plane elongation of the bolt-holes caused by bearing against the bolt-shanks. To t...
Article
Full-text available
Experimental tests have previously shown that the strength of bolted moment-connections between cold-formed steel channel members, where the connections are formed through an array of bolts in the web, is dependent on the length of the bolt-group. This reduced strength has been observed in tests on portal frame joints as well as overlapped purlin j...
Article
Full-text available
This paper presents an experimental and numerical investigation into cold-formed steel portal frame moment-resisting joints, having bolts in both the web and outer flange. The bearing resistance and stiffness of threaded bolt shanks in single and double shear lapped connections are determined experimentally. A total of seven four-point bending test...
Article
Full-text available
Aluminium alloy has recently become popular in New Zealand's construction sector as a sustainable building material. However, in roll-formed aluminium alloy (RFA) channel beams, particularly those having web holes, cripples at points of concentrated or localised loading. In this paper, end-two-flange (ETF) web crippling behaviour of RFA unlipped ch...
Article
Full-text available
Cold-formed steel (CFS) is a popular form of construction in New Zealand and the developed world because it can be cost-effective, durable, sustainable, resilient to extreme environmental and seismic loads and easy to install. When used in domestic and medium-rise buildings, T-Stub connection between CFS channel sections is formed by using self-dri...
Article
Full-text available
The traditional linear economy (LE) approach based on a “take-make-dispose” plan that has been used in building activities over a long period has a significant impact on the environment. In the LE approach, the used materials are usually sent to landfills rather than recycled, resulting in resource depletion and excessive carbon emissions. A circul...
Article
Full-text available
This work presents a deep-learning model referred to as a deep belief network (DBN) to investigate the end-two-flange (ETF) web crippling behaviour of roll-formed aluminium alloy channels (both unfastened and fastened to the supports) with centred and offset web circular holes. A total of 1,080 data points was generated for training the DBN, using...
Article
This paper investigates the structural behaviour of cold-formed steel (CFS) back-to-back (BTB) channel sections subjected to axial compression at elevated temperatures. The stress-strain curves of G250 grade CFS channels at ambient and elevated temperatures were taken from the literature, where the temperature varied from 20 to 700 ℃. A detailed pa...
Article
Full-text available
A novel machine learning model, eXtreme Gradient Boosting (XGBoost), was used for the purpose of evaluating the moment capacity of cold-formed steel (CFS) channel beams with edge-stiffened web holes subject to bending. A total of 1,620 data points were generated for training the XGBoost model, using an elasto-plastic finite element model which was...
Article
This study presents a novel machine-learning model using the eXtreme Gradient Boosting (XGBoost) tool, for assessing the web crippling behaviour of perforated roll-formed aluminium alloy (RFA) unlipped channels (both fastened and unfastened) under interior-two-flange loading. A total of 1,080 data points were generated for training the XGBoost mode...
Article
Full-text available
This paper presents the results of 81 experimental tests on the design strength of power-actuated fasteners (PAFs) in single shear connections for a light gauge steel framing (LGSF), as an alternative to self-drilling screws for selective uses. This type of connection can be employed to install a reinforcing plate on one or both sides of the frame,...
Article
Full-text available
Aluminium alloy back-to-back channels are becoming popular in building structures. These back-to-back channels often include web hole for installation of services. No previous research, however, is available in the literature for compressive behaviour of such aluminium alloy back-to-back channels with web hole. This paper presents an experimental a...
Article
Full-text available
The construction and building sectors are currently responsible globally for a significant share of the total energy consumption and energy-related carbon dioxide emissions. The use of Modern Methods of Construction can help reduce this, one example being the use of cold-formed steel (CFS) construction. CFS channel sections have inherent advantages...
Article
Full-text available
Cold-formed steel (CFS) systems have seen an increased application in the past few decades, especially in the construction of low- to mid-rise buildings. CFS members offer considerable structural and environmental advantages, such as low weight, ease and speed of construction, greater manufacturing flexibility, recyclability and low embodied carbon...
Article
Full-text available
Cold-formed steel (CFS) self-drilling screw connections are popular in construction industry due to rapid fastening and ease of installation. However, the performance of the CFS connections is very critical when they are exposed to corrosive environments such as humid and acidic or chloride-rich environments. The corrosion damage of CFS structures...
Article
Full-text available
This paper investigates the interior-one-flange web crippling strength of cold-formed steel channels at elevated temperatures. The stress-strain curves of G250 and G450 grade cold-formed steel (CFS) channels at ambient and elevated temperatures were taken from the literature and the temperatures were varied from 20 to 700 ◦C. A detailed parametric...
Conference Paper
Cold-formed steel (CFS) self-drilling screw connections are popular in the construction industry due to rapid fastening and ease of installation. However, the corrosion damage of CFS structures can significantly reduce mechanical properties, affecting the safety and durability of such structures. Therefore, this research investigates the effect of...
Article
Aluminium alloy back-to-back channels are becoming popular in building structures. These back-to-back channels often include web holes for installation of services. No previous research, however, is available in the literature for compressive behaviour of aluminium alloy back-to-back channels with web holes. This paper presents an experimental and...
Article
Full-text available
This paper investigates the post-buckling behaviour and axial capacity of thin-walled steel stiffened single-channel sections (ISSCS) and back-to-back stiffened channel sections (BISCS). BISCS were connected using fasteners at a spacing of 200 mm and with an edge distance of 100 mm. Under axial compression, 10 new ISSCS and BISCS columns with fixed...
Article
Full-text available
This paper investigates the axial compression capacity of cold-formed steel (CFS) equal angle sections with complex edge stiffeners. Both experimental and numerical analyses were carried out. In total, 10 tests were carried out and its results are presented in this paper. Preceding to compression tests, the material properties were determined and i...
Conference Paper
Full-text available
This paper investigates the seismic performance of a single storey moment resisting cold-formed steel (CFS) portal frame through cyclic testing. Six monotonic and six cyclic tests were performed on three different section sizes of CFS portal frames. The portal frames were 3.2m long x 2.2m high and the CFS sections bolted with either perfect-fit tol...
Article
Full-text available
In New Zealand (NZ), steel roofing is the most common roofing type for residential buildings. However, the environmental impact of steel roofs are not negligible. Steel roofs account for up to 30% of the upfront embodied carbon for a typical NZ house, highlighting the importance of investigating and reducing the environmental impacts of steel roofs...
Article
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This paper reports on experiments addressing the buckling and collapse behaviour of an innovative built-up cold-formed steel (CFS) columns. The built-up column consists of four individual CFS lipped channels, two of them placed back-to-back at the web using two self-drilling screw fasteners at specified spacing along the column length, while the ot...
Article
Full-text available
This paper presents a numerical study on structural behaviour of cold-formed stainless steel channels with circular web holes, under interior-one-flange loading case. The material properties of stainless steel types EN 1.4509 (Ferritic), EN 1.4462 (Duplex) and EN 1.4301 (Austenitic) were taken from the literature. In order to study the influence of...
Conference Paper
Full-text available
This paper presents an experimental and numerical investigation on axial capacity of built-up cold-formed steel (CFS) box section columns under axial compression. A total of 16 tests covering different values of slenderness are reported. Of these, 8 tests were conducted on built-up CFS box sections and the remaining 8 tests were conducted on single...
Article
Full-text available
In cold-formed steel (CFS) structures, such as trusses, transmission towers and portal frames, the use of back-to-back built-up CFS unequal angle sections are becoming increasingly popular. In such an arrangement, intermediate welds or screw fasteners are required at discrete points along the length, preventing the angle sections from buckling inde...
Article
Full-text available
Prefabricated house-building companies, as suppliers or supply chains, which use manufacturing as a business approach towards industrialisation, struggle to implement principles and optimal practices driven from well-established and validated theories in operational research. Supply chain management has a mature body of knowledge that has been wide...
Conference Paper
Full-text available
Cold-formed steel (CFS) self-drilling screw connections are popular due to rapid fastening and ease of installation. This paper presents the results of 25 new experimental tests that investigate the effect of screw patterns, number of screws, and screw spacing on the connection strength; in the tests, 12 and 14 gauge screws are considered. The desi...
Conference Paper
Full-text available
Recently, a new generation of cold-formed steel (CFS) channel sections with edge-stiffened web openings has been developed and is widely used in New Zealand. However, no experimental investigation in the literature has been reported for such channel sections under axial compression. In this paper, a total of 26 axial compression tests are reported...
Article
In current design standards, cold-formed steel (CFS) beam-column elements are generally designed by considering fully warping free behaviour in their supports, which means the benefit of warping-restrained boundary conditions is neglected. In addition, while a non-linear relationship governs the interaction of axial compression and bending, simplif...
Article
Full-text available
This research undertakes a Life Cycle Analysis (LCA) to determine the climate change potential of a typical newly built steel detached dwelling in Palmerston North, New Zealand (NZ), and assesses its results concerning the 2° C and 1.5° C 2050 Paris Agreement targets. The proposed, upcoming policy and actions of the NZ government relating to its re...
Article
This paper proposes a novel cold-formed portal framing system that comprises tapered box members formed from two cold-formed nested channel sections. The proposed method possesses structural and non-structural advantages such as improved seismic performance, enhanced building hygiene through bird and dust resistance, further corrosion resistance, a...
Article
Pakistan’s as developing economy is in crisis due to rising energy and water demand. This study considers the Green Building concept as it accounts for optimum use of energy and water conservation. A building information modelling approach has been used to analyze the Green Building concepts. Parameters of Green Building are defined within Leadersh...
Article
Full-text available
In this paper, a total of 254 results comprising 30 tests and 224 finite element (FE) analysis results were reported. Simply supported test specimens of CFS channels with aspect ratios of 1.0 and 1.5 were tested. For comparison, specimens with un-stiffened web holes and plain webs were also tested. A nonlinear elasto-plastic FE model was then devel...
Article
An experimental investigation of 12 screw fastened back-to-back built-up aluminium alloy slender columns under axial compression is presented, complemented by a numerical finite element study comprising 246 results. Using a laser scanner, the geometric imperfections were measured. In the numerical study, the effect of the modified slenderness, numb...
Article
Full-text available
In New Zealand, housing is typically low density, with light timber framing being the dominant form of construction with more than 90% of the market. From 2020, as a result of the global pandemic, there was a shortage of timber in New Zealand, resulting in increased popularity for light steel framing, the main alternative to timber for housing. At...
Conference Paper
Full-text available
This paper investigates the structural behaviour of cold-formed steel (CFS) back-to-back built-up equal and unequal angle section columns. In total, the results from 16 experimental tests on back-to-back built-up CFS screw fastened equal angle sections and 4 tests on back-to-back built-up CFS screw fastened and welded unequal angles are reported, w...
Article
This paper presents a finite element analysis of cold-formed stainless steel channels with circular web holes, subjected to end-one-flange loading condition. The material properties of stainless steel types EN 1.4509 (Ferritic), EN 1.4462 (Duplex) and EN 1.4301 (Austenitic) were taken from the literature. To investigate the effect of web hole size,...
Article
Full-text available
This paper presents an experimental investigation on the load-bearing capacities of stainless steel hybrid tubular K-joints with square braces and circular chord. All test specimens were made from austenitic stainless steel of grade AISI 304. For gapped K-joints, as the gap (g) increased, initial stiffness and load-bearing capacities of joints decr...
Article
Full-text available
Cold-formed steel (CFS) Tab connections are popular due to their rapid fastening and ease of installation, and their applications have increased recently in Pacific countries, including Australia and New Zealand. This type of connection consists of a Tab plate formed from the web of the supporting beam and is screwed to the joist web, providing a d...
Article
This study was undertaken to further knowledge in relation to the effect of elevated temperature on performance of adhesively bonded CFRP-to-steel joints subjected to peel loading. Two epoxy adhesives, Adhesive A and Adhesive B, were assessed with regard to their aging behaviour at two elevated temperatures and for two exposure periods. Adhesive co...
Article
Exposure to environmental stresses can weaken the connection of epoxy-bonded CFRP-strengthened steel elements. As a result, designers often express concern about possible premature delamination arising from combined peel and shear effects at the CFRP-steel interface. This study was undertaken to further knowledge in relation to the peel failure of...
Article
Full-text available
Recently, a new generation of cold-formed steel (CFS) channel section with edge-stiffened web holes has been developed by industry in New Zealand. However, no research has been reported in the literature to investigate the axial capacity of back-to-back channels with edge-stiffened web holes. This paper presents a total of 73 new results comprising...
Article
This paper investigates the seismic performance of a single storey moment resisting cold-formed steel (CFS) portal frame through cyclic testing. Six monotonic and six cyclic tests were performed on three different section sizes of CFS portal frames. The portal frames were 3.2m long x 2.2m high and the CFS sections bolted with either perfect-fit tol...
Article
Full-text available
Using a novel experimental test setup, the behaviour of composite floor slab interfaces having different deck rib orientation and end anchorage detail has been investigated. In the first floor slab configuration, the deck rib orientation was parallel to the supporting beam. For the second and third floor slab configurations, the deck rib orientatio...
Article
Full-text available
In Cold-formed steel (CFS) structures, such as trusses, transmission towers and portal frames, the use of back-to-back built-up CFS unequal angle sections are becoming increasingly popular. In such an arrangement, screw fasteners are required at discrete points along the length to prevent the unfdequal angle-sections from buckling independently. No...
Article
The work presented in this paper investigates the strength of moment-resisiting apex brackets of cold-formed steel portal frames. The results of two previously reported full-scale portal frame tests, where the frames failed through buckling of the apex bracket, were used to validate a finite element model that included material nonlinearity, geomet...
Article
Full-text available
This paper proposes a deep-learning framework, specifically, a deep belief network (DBN), for studying the web crippling performance of cold-formed stainless steel channel sections (lipped and unlipped as well as fastened and unfastened) with cantered and offset web holes under the end-two-flange loading condition. G430 ferritic, S32205 duplex and...
Article
Full-text available
This paper proposes a framework of deep belief network (DBN) for studying the structural performance of cold-formed steel (CFS) channel sections with edge-stiffened/un-stiffened web holes, under axial compression. A total of 50,000 data points for training the DBN are generated from elasto plastic finite element analysis, which incorporates both in...
Article
Full-text available
This paper presents an experimental and numerical investigation into the buckling behaviour of axially loaded cold-formed steel (CFS) zed and hat sections. In total, 12 experimental tests are reported, of those 6 tests are on CFS zed sections and the remaining 6 are on CFS hat sections. The failure modes, ultimate loads, and load-displacement curve...
Article
Full-text available
In this study, a deep learning-based axial capacity prediction for cold-formed steel channel sections is developed using Deep Belief Network (DBN). A total of 10,500 data points for training the DBN are generated from non-linear elasto plastic finite element analysis, which incorporated both initial imperfections, as recommended by the Australian/N...
Article
Full-text available
This paper presents a finite-element (FE) investigation on the bearing capacity of stainless steel hybrid tubular K-joints with square braces and circular chord. The nonlinear finite-element (FE) models were developed and validated against the test results available in the literature, which were then used to conduct a parametric study including 162...
Article
In cold-formed steel structures, such as trusses, wall frames and portal frames, the use of back-to-back built-up cold-formed stainless steel unlipped channels as compression members are becoming popular. The advantages of using stainless steel as structural members are corrosion resistance and durability, compared with carbon steel. Current guidan...
Article
Full-text available
This paper describes a numerical study on stress concentration factors (SCFs) of stainless-steel hybrid tubular T-, Y- and X-joints with circular hollow sections (CHSs) and with square hollow sections (SHSs). The finite element models (FE models) were developed and validated against the corresponding test results available in the literature. The va...
Article
Full-text available
The use of aluminium alloy channel sections is becoming popular in lightweight structures, especially for pillars of curtain wall systems and brace and chord members in roof trusses. In cases where increased axial strength is required, it is popular to use built-up sections, instead of single channel sections. Back-to-back built-up aluminium alloy...
Article
Full-text available
Cold-formed steel (CFS) channels with edge-stiffened web holes are widely used as flooring joists and bearers in industrial buildings and their flanges are fastened in most cases. This prevents the rotation of flanges and increases their web crippling capacity. In the literature, no information is available on the web crippling capacity of such fas...
Article
This paper presents the results of a finite element investigation on cold-formed steel (CFS) channel sections with circular web holes under end-two-flange (ETF) loading condition and subjected to elevated temperatures. The stress strain curve for G250 grade of CFS with 1.95 mm thickness at elevated temperatures was taken from Kankanamge and Mahendr...