Web crippling behaviour of C-section beams with web ribs

SupaCee section is one of the cold-formed steel members which is increasingly used in the construction sector. It is characterized by unique ribbed web and curved lip elements, and is claimed to be more economical with extra strength than the traditional channel sections. SupaCee sections are widely used in Australia as floor joists, bearers, purlins and girts. Many experimental and numerical studies have been carried out to evaluate the behaviour and design of conventional channel beams subject to web crippling. To date, however, no investigation has been conducted into the web crippling behaviour and strength of SupaCee sections. Current cold-formed steel design equations do not include any design procedures for SupaCee sections. Hence experimental studies were conducted to assess the web crippling behaviour and strengths of SupaCee sections under ETF and ITF load cases. Thirty six web crippling tests were conducted and the capacity results were compared with the predictions from the AS/NZS 4600 and AISI design rules developed for conventional channel sections. Comparison of ultimate web crippling capacities from tests showed that AS/NZS 4600 and AISI design equations are unconservative for SupaCee sections under ETF load case, but are overly conservative for ITF load case. Hence new equations were proposed to determine the web crippling capacities of SupaCee sections based on the experimental results from this study. Suitable design rules were also developed within the direct strength method format. This paper presents the details of this experimental study of SupaCee sections subject to web crippling and the results.

Changes in teachers’ behaviour in secondary science education : implementing a standards-referenced national curriculum

There is substantial attention worldwide to the quality of secondary school teaching in STEM in Education. This paper reports on the use of Outcome Mapping (OM) as an approach to guide and monitor change in teacher practice and a visual tool, shaped as a Star, to benchmark and monitor this behaviour. OM and the visual tool were employed to guide and document three secondary teachers’ behaviour as they planned, implemented and assessed a science unit in the new Australian standards-referenced curriculum. Five key outcome markers in the teachers’ behaviour were identified together with progress markers — cumulative qualitative indicators — leading to these outcomes. The use of a Star to benchmark and track teachers’ behaviours was particularly useful because it showed teacher behaviour on multiple dimensions simultaneously at various points in time. It also highlighted priorities in need of further attention and provided a pathway to achievement. Hence, OM and the Star representation provide both theoretical and pragmatic approaches to enhancing quality in STEM teaching.

An application of the Driver Behaviour Questionnaire in a large Australian organisational fleeting setting : can it predict crashes and demerit point loss?

This study reports on the utilisation of the Manchester Driver Behaviour Questionnaire (DBQ) to examine the self-reported driving behaviours of a large sample of Australian fleet drivers (N = 3414). Surveys were completed by employees before they commenced a one day safety workshop intervention. Factor analysis techniques identified a three factor solution similar to previous research, which was comprised of: (a) errors, (b) highway-code violations and (c) aggressive driving violations. Two items traditionally related with highway-code violations were found to be associated with aggressive driving behaviours among the current sample. Multivariate analyses revealed that exposure to the road, errors and self-reported offences predicted crashes at work in the last 12 months, while gender, highway violations and crashes predicted offences incurred while at work. Importantly, those who received more fines at work were at an increased risk of crashing the work vehicle. However, overall, the DBQ demonstrated limited efficacy at predicting these two outcomes. This paper outlines the major findings of the study in regards to identifying and predicting aberrant driving behaviours and also highlights implications regarding the future utilisation of the DBQ within fleet settings.

Modelling of the mechanical behaviour of heavily over-consolidated bagasse

A better understanding of the behaviour of prepared cane and bagasse, and the ability to model the mechanical behaviour of bagasse as it is squeezed in a milling unit to extract juice, would help identify how to improve the current process, for example to reduce final bagasse moisture. Previous investigations have proven that juice flow through bagasse obeys Darcy’s permeability law, that the grip of the rough surface of the grooves on the bagasse can be represented by the Mohr-Coulomb failure criterion for soils, and that the internal mechanical behaviour of the bagasse is critical state behaviour similar to that for sand and clay. Current Finite Element Models (FEM) available in commercial software have adequate permeability models. However, no commercially available software seems to contain an adequate mechanical model for bagasse. The same software contains a few material models for soil and other materials, while the coding of hundreds of developed models for soil and other materials remains confidential at universities and government research centres. Progress has been made in the last ten years towards implementing a mechanical model for bagasse in finite element software code. This paper builds on that progress and carries out a further step towards obtaining an adequate material model. The fifth and final loading condition outlined previously, shearing of heavily over-consolidated bagasse, is outlined.

Psychotropics and challenging behaviour in people with an intellectual disability

Hilmer and Gnjidic drew attention to the pharmacological management of behavioural problems in nursing home residents, and called for a reduction in inappropriate prescribing and the development of alternative management strategies.1 We extend these concerns to another vulnerable population — people with intellectual disability. Historically, this population is one of the most medicated groups in modern society.

Resistances, facilitators and influences on professionals' knowledge sharing behaviour : a case study

The centrality of knowledge sharing to organisations' sustainability has been established. This case study illustrates the influences on individual knowledge sharing decision-making and behaviour among professionals and paraprofessionals - specifically civil engineers and design drafters - in a large public sector organisation that provides transportation infrastructure. The case examines the ways in which overlapping sets of values and behavioural drivers affect knowledge sharing orientation and practices in a collective of experts and novices working in an environment that is largely project-based. The alignment among sector, profession and organisation values provides a supportive environment for knowledge sharing, however individual behaviour is found to be most strongly influenced by the presence and quality of relational capital.

Synthesis, characterization and comparative OFET behaviour of indenofluorene-bithiophene and terthiophene alternating copolymers

The synthesis of alternating copolymers of tetraalkylindenofluorene with bithiophene and terthiophene using Suzuki polycondensation route is reported. We report on the optical and electrochemical properties of these copolymers. AFM analysis of the microscopic morphology of thin deposits showed that the copolymer with terthiophene units produced the more ordered films, with well-defined fibrillar structures, resulting from highly-regular dense packing due to strong π-π interchain interactions, in contrast to the amorphous bithiophene copolymer. Upon testing these materials in FETs the terthienyl copolymers displayed the higher charge mobilities among the studied compounds, with values of over 10-4 cm2 V-1 s-1 being obtained.

Synthesis and study of conductivity behaviour of blended conducting polymer films irradiated with swift heavy ions of silicon

In recent times, blended polymers have shown a lot of promise in terms of easy processability in different shapes and forms. In the present work, polyaniline emeraldine base (PANi-EB) was doped with camphor sulfonic acid (CSA) and combined with the conducting polymer polyfluorene (PF) as well as the insulating polymer polyvinyl chloride (PVC) to synthesize CSA doped PANi-PF and PANi-PVC blended polymers. It is well known that PANi when doped with CSA becomes highly conducting. However, its poor mechanical properties, such as low tensile, compressive, and flexural strength render PANi a non-ideal material to be processed for its various practical applications, such as electromagnetic shielding, anti-corrosion shielding, photolithography and microelectronic devices etc. Thus the search for polymers which are easily processable and are capable of showing high conductivity still continues. PANi-PVC blend was prepared, which showed low conductivity which is limiting factor for certain applications. Therefore, another processable polymer PF was chosen as conducting matrix. Conducting PF can be easily processed into various shapes and forms. Therefore, a blend mixture was prepared by using PANi and PF through the use of CSA as a counter ion which forms a "bridge" between the two polymeric components of the inter-polymer complex. Two blended polymers have been synthesized and investigated for their conductivity behaviour. It was observed that the blended film of CSA doped PANi-PVC showed a room temperature electrical conductivity of 2.8 × 10-7 S/cm where as the blended film made by CSA doped PANi with conducting polymer PF showed a room temperature conductivity of 1.3 × 10-5 S/cm. Blended films were irradiated with 100 MeV silicon ions with a view to increase their conductivity with a fluence ranging from 1011 ions to 1013 per cm2 from 15 UD Pelletron accelerator at NSC, New Delhi.

Where do consumers draw the line? : an investigation of deviant consumer behaviour

Using mixed-methods, this research investigated why consumers engage in deviant behaviors. It found that there is significant variation in how consumers perceive right and wrong, which calls for more tailored deterrence strategies to challenge how consumers justify deviant behaviours. Specifically, individuals draw on a number of factors when assessing right and wrong. While individuals agree on the polar acceptable and unacceptable behaviours, behaviours in between are questionable. When social consensus varies on a behaviour's acceptability, so to do the predictors of deviant behaviour. These findings contribute to consumer deviance and consumer ethics research.

Antisocial behaviour orders : Unanticipated directions in social network site development

Abstract: Social network technologies, as we know them today have become a popular feature of everyday life for many people. As their name suggests, their underlying premise is to enable people to connect with each other for a variety of purposes. These purposes however, are generally thought of in a positive fashion. Based on a multi-method study of two online environments, Habbo Hotel and Second Life, which incorporate social networking functionality, we she light on forms of what can be conceptualized as antisocial behaviours and the rationales for these. Such behaviours included: scamming, racist/homophobic attacks, sim attacks, avatar attacks, non-conformance to contextual norms, counterfeiting and unneighbourly behaviour. The rationales for sub behaviours included: profit, fun, status building, network disruption, accidental acts and prejudice. Through our analysis we are able to comment upon the difficulties of defining antisocial behaviour in such environments, particularly when such environments are subject to interpretation vis their use and expected norms. We also point to the problems we face in conducting our public and private lives given the role ICTs are playing in the convergence of these two spaces and also the convergence of ICTs themselves.

The impact of mobile phone distraction on the braking behaviour of young drivers : a hazard-based duration model

Braking is a crucial driving task with a direct relationship with crash risk, as both excess and inadequate braking can lead to collisions. The objective of this study was to compare the braking profile of young drivers distracted by mobile phone conversations to non-distracted braking. In particular, the braking behaviour of drivers in response to a pedestrian entering a zebra crossing was examined using the CARRS-Q Advanced Driving Simulator. Thirty-two licensed drivers drove the simulator in three phone conditions: baseline (no phone conversation), hands-free, and handheld. In addition to driving the simulator, each participant completed questionnaires related to driver demographics, driving history, usage of mobile phones while driving, and general mobile phone usage history. The drivers were 18–26 years old and split evenly by gender. A linear mixed model analysis of braking profiles along the roadway before the pedestrian crossing revealed comparatively increased decelerations among distracted drivers, particularly during the initial 20 kph of deceleration. Drivers’ initial 20 kph deceleration time was modelled using a parametric accelerated failure time (AFT) hazard-based duration model with a Weibull distribution with clustered heterogeneity to account for the repeated measures experiment design. Factors found to significantly influence the braking task included vehicle dynamics variables like initial speed and maximum deceleration, phone condition, and driver-specific variables such as licence type, crash involvement history, and self-reported experience of using a mobile phone whilst driving. Distracted drivers on average appear to reduce the speed of their vehicle faster and more abruptly than non-distracted drivers, exhibiting excess braking comparatively and revealing perhaps risk compensation. The braking appears to be more aggressive for distracted drivers with provisional licenses compared to drivers with open licenses. Abrupt or excessive braking by distracted drivers might pose significant safety concerns to following vehicles in a traffic stream.

Flexural–torsional buckling behaviour and design of cold-formed steel compression members at elevated temperatures

Current design rules for the member capacities of cold-formed steel columns are based on the same non-dimensional strength curve for both fixed and pinned-ended columns at ambient temperature. This research has investigated the accuracy of using current ambient temperature design rules in Australia/New Zealand (AS/NZS 4600), American (AISI S100) and European (Eurocode 3 Part 1.3) standards in determining the flexural–torsional buckling capacities of cold-formed steel columns at uniform elevated temperatures using appropriately reduced mechanical properties. It was found that these design rules accurately predicted the member capacities of pin ended lipped channel columns undergoing flexural torsional buckling at elevated temperatures. However, for fixed ended columns with warping fixity undergoing flexural–torsional buckling, the current design rules significantly underestimated the column capacities as they disregard the beneficial effect of warping fixity. This paper has therefore recommended the use of improved design rules developed for ambient temperature conditions to predict the axial compression capacities of fixed ended columns subject to flexural–torsional buckling at elevated temperatures within AS/NZS 4600 and AISI S100 design provisions. The accuracy of the proposed fire design rules was verified using finite element analysis and test results of cold-formed lipped channel columns at elevated temperatures except for low strength steel columns with intermediate slenderness whose behaviour was influenced by the increased nonlinearity in the stress–strain curves at elevated temperatures. Further research is required to include these effects within AS/NZS 4600 and AISI S100 design rules. However, Eurocode 3 Part 1.3 design rules can be used for this purpose by using suitable buckling curves as recommended in this paper.

Distortional buckling behaviour of fire exposed cold-formed steel columns

Cold-formed steel sections are commonly used in low-rise commercial and residential buildings. During fire events, cold-formed steel structural elements in these buildings can be exposed to elevated temperatures. Hence after such events there is a need to evaluate their residual strengths. However, only limited information is available in relation to the residual strength of fire exposed cold-formed steel sections. This research is aimed at investigating the distortional buckling capacities of fire exposed cold-formed lipped channel sections. A series of compression tests of fire exposed, short lipped channel columns made of varying steel grades and thicknesses was undertaken in this research. Test columns were first exposed to different elevated temperatures up to 800 oC, and then tested to failure after cooling down. Suitable finite element models were developed with post-fire mechanical properties to simulate the behaviour of tested columns and were validated using test results. The residual compression capacities of short columns were also predicted using the current cold-formed steel standards and compared with test and finite element analysis results. This comparison showed that ambient temperature design rules for columns can be used to predict the residual compression capacities of fire exposed short or laterally restrained cold-formed steel columns provided the maximum temperature experienced by the column can be estimated after a fire event. Such residual capacity assessments will allow engineers to evaluate the safety of fire exposed buildings. This paper presents the details of this experimental study, finite element analyses and the results.

Experimental studies on web crippling behaviour of hollow flange channel beams under two flange load cases

This paper presents the details of an experimental study of a cold-formed steel hollow flange channel beam known as LiteSteel beam (LSB) subject to web crippling under End Two Flange (ETF) and Interior Two Flange (ITF) load cases. The LSB sections with two rectangular hollow flanges are made using a simultaneous cold-forming and electric resistance welding process. Due to the geometry of the LSB, and its unique residual stress characteristics and initial geometric imperfections, much of the existing research for common cold-formed steel sections is not directly applicable to LSB. Experimental and numerical studies have been carried out to evaluate the behaviour and design of LSBs subject to pure bending, predominant shear and combined actions. To date, however, no investigation has been conducted on the web crippling behaviour and strength of LSB sections. Hence an experimental study was conducted to investigate the web crippling behaviour and capacities of LSBs. Twenty-eight web crippling tests were conducted under ETF and ITF load cases, and the ultimate web crippling capacities were compared with the predictions from the design equations in AS/NZS 4600 and AISI S100. This comparison showed that AS/NZS 4600 and AISI S100 web crippling design equations are unconservative for LSB sections under ETF and ITF load cases. Hence new equations were proposed to determine the web crippling capacities of LSBs based on experimental results. Suitable design rules were also developed under the direct strength method (DSM) format.