Shear strength of hollow flange channel beams with stiffened web openings

This LiteSteel beam (LSB) is a new cold-formed steel hollow flange channel section produced using a patented manufacturing process involving simultaneous cold-forming and dual electric resistance welding. The LSBs are commonly used as floor joists and bearers with web openings in buildings. Their shear strengths are considerably reduced when web openings are included for the purpose of locating building services. Shear tests of LSBs with web openings have shown that there is up to 60% reduction in the shear capacity. Hence there is a need to improve the shear capacity of LSBs with web openings. A cost effective way to eliminate the shear capacity reduction is to stiffen the web openings using suitable stiffeners. Hence numerical studies were undertaken to investigate the shear capacity of LSBs with stiffened web openings. In this research, finite element models of LSBs with stiffened web openings in shear were developed to simulate the shear behaviour and strength of LSBs. Various stiffening methods using plate and LSB stiffeners attached to LSBs using both welding and screw-fastening were attempted. The developed models were then validated by comparing their results with experimental results and used in further studies. Both finite element and experimental results showed that the stiffening arrangements recommended by past research for cold-formed steel channel beams are not adequate to restore the shear strengths of LSBs with web openings. Therefore new stiffener arrangements were proposed for LSBs with web openings. This paper presents the details of this research project using numerical studies and the results.

Finite element analyses of lipped channel beams with Web openings in shear

Cold-formed steel members are increasingly used as primary structural elements in buildings due to the availability of thin and high strength steels and advanced cold-forming technologies. Cold-formed lipped channel beams (LCB) are commonly used as flexural members such as floor joists and bearers. Shear behaviour of LCBs with web openings is more complicated and their shear capacities are considerably reduced by the presence of web openings. However, limited research has been undertaken on the shear behaviour and strength of LCBs with web openings. Hence a numerical study was undertaken to investigate the shear behaviour and strength of LCBs with web openings. Finite element models of simply supported LCBs with aspect ratios of 1.0 and 1.5 were considered under a mid-span load. They were then validated by comparing their results with test results and used in a detailed parametric study. Experimental and numerical results showed that the current design rules in cold-formed steel structures design codes are very conservative for the shear design of LCBs with web openings. Improved design equations were therefore proposed for the shear strength of LCBs with web openings. This paper presents the details of this numerical study of LCBs with web openings, and the results.

Social media and Web 2.0 : teacher-librarians, risk and inequity

This paper reports research into teacher-­‐librarians’ perceptions of using social media and Web 2.0 in teaching and learning. A pilot study was conducted with teacher-­‐librarians in five government schools and five private schools in southeast Queensland. The findings revealed that there was a strong digital divide between government schools and private schools, with government schools suffering severe restrictions on the use of social media and Web 2.0, leading to an unsophisticated use of these technologies. It is argued that internet ‘over-­‐ blocking’ may lead to government school students not being empowered to manage risks in an open internet environment. Furthermore, their use of information for academic and recreational learning may be compromised. This has implications particularly for low socioeconomic students, leading to further inequity in the process and outcomes of Australian education.

School libraries, teacher-librarians and their contribution to student literacy development in Gold Coast schools

This is the first research focusing on Gold Coast school libraries and teacher- librarians. It presents a detailed picture of library provision and staffing at a representative group of 27 government and non-government schools at the Gold Coast. It shows links between employment of a teacher-librarian and higher NAPLAN reading and writing scores. And it presents the principals’ generally positive views about teacher-librarians’ contribution to reading and literacy at their schools. The findings respond in part to the recent government inquiry’s call (House of Representatives, 2011) for research about the current staffing of school libraries in Australia, and the influence of school libraries and teacher-librarians on students’ literacy and learning outcomes. While the study has focused on a relatively small group of school libraries, it has produced a range of significant outcomes: • An extensive review of international and Australian research showing impacts of school libraries and teacher-librarians on students’ literacy and learning outcomes • Findings consistent with international research showing: - An inverse relationship between lower student to EFT library staff ratio and higher school NAPLAN scores for reading and writing - Schools that employ a teacher-librarian tend to achieve school NAPLAN scores for respective year levels that are higher than the national mean It is anticipated that the study’s findings will be of interest to education authorities, school leadership teams, teacher-librarians, teachers and researchers. The findings provide evidence to: • inform policy development and strategic planning for school libraries that respond to the literacy development needs of 21st century learners • inform school-based management of school libraries • inform curriculum development and teacher-librarian practice • support further collaborative research on a State or national level • enhance conceptual understandings about relationship(s) between school libraries, teacher-librarians and literacy/information literacy development • support advocacy about school libraries, teacher-librarians and their contribution to literacy development and student learning in Australian schools SLAQ President Toni Leigh comments: “It is heartening to see findings which validate the critical role teacher-librarians play in student literacy development and the positive correlation of higher NAPLAN scores and schools with a qualified teacher-librarian. Also encouraging is the high percentage of school principals who recognise the necessity of a well resourced school library and the positive influence of these libraries on student literacy”. This research arises from a research partnership between School Library Association of Queensland (SLAQ) and Children and Youth Research Centre, QUT. Lead researcher: Dr Hilary Hughes, Children and Youth Research Centre, QUT Research assistants: Dr Hossein Bozorgian, Dr Cherie Allan, Dr Michelle Dicinoski, QUT SLAQ Research Reference Group: Toni Leigh, Marj Osborne, Sally Fraser, Chris Kahl and Helen Reynolds Reference: House of Representatives. (2011). School libraries and teacher librarians in 21st century Australia. Canberra: Commonwealth of Australia. http://www.aph.gov.au/Parliamentary_Business/Committees/House_of_Representatives_Committees?url=ee/schoollibraries/report.htm

Teaching end-user remote online searching

The Queensland University of Technology (QUT) Library bas recently commenced teaching higher degree students to search online systems such as BRS, ORBIT and STN. The emphasis is on education rather than training. with students being required to familiarise themselves with system commands and database structures whilst receiving necessarily limited tutorial help. The teaching strategies used and problems encountered in the program are outlined. Student responses to the experience of learning to online search are discussed.

Postgraduate response to an information retrieval credit course

Information skills instruction for research candidates bas recently been formalised as coursework at the Queensland University of Technology. Feedback solicited from participants suggests that students benefit from such coursework in a number of ways. Their perception of the value of specific content areas to their literature review and thesis presentation is favourable. A small group of students who participated in Interviews identified five ways in which the coursework assisted the research process. As Instructors continue to work with the post��graduate community it would be useful to deepen our understanding of how such instruction is perceived and the benefits which can be derived from it.

Information skills coursework for postgraduate students : investigation and response at the Queensland University of Technology

In response to current developments In the tertiary education sector, the Queensland University of Technology Library has mounted an Intensive course - Advanced Information Retrieval Skills - for higher degree students. In determining need for such a course, a survey of postgraduate students and their supervisors was conducted. Results of this survey are discussed and details of the four credit point subjects are outlined.

Information literacy : a theoretical framework for higher education

Information literacy has been a significant issue in the library community for many years. It is now being recognised as an important issue by the higher education community. This theoretical framework draws together important elements of the information literacy agenda specifically for tertiary educators and administrators. The frame-work examines three areas of primary concern: the possible outcomes of information literacy education (through outlining the characteristics of information literate people); the nature of information literacy education; and the potential role of stake-holders (including information services, faculty, staff developers and learning counsellors) in helping staff and students to be information literate. This theoretical framework forms part of the Griffith University Information Literacy Blueprint. The Blueprint was designed between June and August of 1994. The project, a quality initiative of the Division of Information Services, was led by Janice Rickards, University Librarian.

School libraries, teacher-librarians and literacy at Gold Coast schools : research findings

This paper reports research about school libraries, teacher-librarians and their contribution to literacy development. It presents an evidenced based snapshot, from the principals’ perspective, of 27 school libraries in the Gold Coast area of Australia. These new Australian findings show: • an evidenced based snapshot of school libraries and teacher-librarians, from the principals’ perspective • indications that school NAPLAN scores for reading and writing were generally higher when (a) student to library staff ratios were lower (i.e. better) and (b) the school had a teacher-librarian. The research responds to the Australian Government inquiry into school libraries and teacher-librarians (2010-11) which identified an urgent need for current data about provision and staffing of school libraries and their influence on student literacy and learning. In light of the National plan for school improvement (Australian Government, 2013), the findings are of potential interest to education authorities, school leadership teams, teacher-librarians, teachers and researchers. They offer evidence to inform policy development, strategic planning and advocacy about school libraries and teacher-librarians in supporting the reading, literacy and learning needs of 21st century learners.

The buckling behaviour of hollow flange beams

A new cold formed structural section known as the hollow flange beam is currently under development in Australia. This section will have many applications, particularly in portal frame buildings. This paper discusses the lateral distortional buckling behaviour of the hollow flange beam.

Strength of stiffened plates with openings

The load-deflection and ultimate strength behaviour of longitudinally stiffened plates with openings was studied using a second-order elastic post-buckling analysis and a rigid-plastic analysis. The ultimate strength was predicted from the intersection point of elastic and rigid-plastic curves and the Perry strut formula. Comparison with experimental results shows that satisfactory prediction of ultimate strength can be obtained by this simple method. Effects of the size of opening, the initial geometrical imperfections and the plate slenderness ratio on the strength of perforated stiffened plates were also studied.

Finite element analysis of hollow flange beams with web stiffeners

A new cold-formed and resistance welded section known as the Hollow Flange Beam (HFB) has been developed recently in Australia. In contrast to the common lateral torsional buckling mode of I-beams, this unique section comprising two stiff triangular flanges and a slender web is susceptible to a lateral distortional buckling mode of failure involving lateral deflection, twist, and cross-section change due to web distortion. This lateral distortional buckling behavior has been shown to cause significant reduction of the available flexural capacity of HFBs. An investigation using finite element analyses and large scale experiments was carried out into the use of transverse web plate stiffeners to improve the lateral buckling capacity of HFBs. This paper presents the details of the finite element model and analytical results. The experimental procedure and results are outlined in a companion paper at this conference.

The modulus of elasticity of steel - is it 200 GPa?

In cold-formed steel construction, the use of a range of thin, high strength steels (0.35 mm thickness and 550 MPa yield stress) has increased significantly in recent times. A good knowledge of the basic mechanical properties of these steels is needed for a satisfactory use of them. In relation to the modulus of elasticity, the current practice is to assume it to be about 200 GPa for all steel grades. However, tensile tests of these steels have consistently shown that the modulus of elasticity varies with grade of steel and thickness. It was found that it increases to values as high as 240 GPa for smaller thicknesses and higher grades of steel. This paper discusses this topic, presents the tensile test results for a number of steel grades and thicknesses, and attempts to develop a relationship between modulus of elasticity, yield stress and thickness for the steel grades considered in this investigation.

Buckling experiments on hollow flange beams with web stiffeners

A new cold-formed and resistance welded section known as the Hollow Flange Beam (HFB) has been developed recently in Australia. In contrast to the common lateral torsional buckling mode of I-beams, this unique section comprising two stiff triangular flanges and a slender web is susceptible to a lateral distortional buckling mode of failure involving lateral deflection, twist and cross-section change due to web distortion. This lateral distortional buckling behaviour has been shown to cause significant reduction of the available flexural strength of HFBs. An investigation using finite element analyses and large scale experiments was carried out into the use of transverse web plate stiffeners to improve the lateral buckling capacity of HFBs. This paper presents the details of the experimental investigation, the results, and the final stiffener arrangement whereas the details of the finite element analyses are presented in a companion paper at this conference.

Pull-through failures of crest-fixed steel claddings initiated by transverse splitting

Crest-fixed steel claddings made of thin, high strength steel often suffer from local pull-through failures at their screw connections during high wind events such as storms and hurricanes. Currently there aren't any adequate design provisions for these cladding systems except for the expensive testing provisions. Since the local pull-through failures in the less ductile steel claddings are initiated by transverse splitting at the fastener hole, analytical studies have not been able to determine the pull-through failure loads. Analytical studies could be used if a reliable splitting criterion is available. Therefore a series of two-span cladding tests was conducted on a range of crest-fixed steel cladding systems under simulated wind uplift loads. The strains in the sheeting around the critical fastener holes were measured until the pull-through failure. This paper presents the details of the experimental investigation and the results including a strain criterion for the local pull-through failure.