Tom Molyneaux

Project-based learning as a contributing factor to graduates’ work readiness

This paper explores what work readiness means for two cohorts of graduate engineers, one from a traditional curriculum, the second from a largely project-based curriculum. Professional bodies and employers have defined a set of attributes for engineering graduates so that graduates will be ‘work ready’. Problem-based learning (PBL) is claimed to be a suitable approach to develop such skills. The graduates were interviewed some months after starting work, along with their managers. All the graduates recognised the benefits of taking PBL subjects as well as vacation work, with success in communication attributed more to PBL. Both cohorts had similar learning outcomes, high skill levels in project management, problem solving, communication skills, research and sustainability. A skills gap in ethics was identified for both cohorts of graduates and their managers. Further work is planned to link skill development with undergraduate learning experience.

An Evaluation of the Learning of Structural Engineering Concepts during the First Two Years of a Project-Based Engineering Degree.

In the modern working environment it is essential for a structural engineer to have an understanding of abstract concepts in structural behaviour and an ability to use them qualitatively. This paper presents the findings of a study on how effectively students acquire such conceptual understanding within a new project/design focused degree course. The new degree programme is described. The first-year students experience a mixture of learning opportunities, including model building/testing, laboratories, workshops/tutorials, and lectures. In the second year there are two design exercises but no formal structural theory course. Specific concepts-based learning material was introduced into the first-year course at mid-semester and the effectiveness of this examined by tests and interviews. The performance of the first-year students is compared to that of the second-year students. The findings show that there is good student engagement and satisfaction with the course and that basic skills are successfully being acquired throughout both years. However, the study highlights areas where concepts are not being adequately developed in the first year and subsequently show little enhancement in the second year.

The effect of using controlled permeability formwork on the durability of concrete containing OPC and PFA

Abstract This paper presents a study to assess the effect of using the controlled permeability formwork (CPF) on the durability of ordinary Portland cement (OPC) and pulverised fuel ash (PFA) based concretes cured for different times. An experimental program has been undertaken in which trial specimens have been tested at various ages following different curing periods and regimes. Various tests were conducted and assessed using a range of destructive and non-destructive techniques such as Schmidt hammer, water permeability, sorptivity absorption, ultrasonic pulse velocity, and chloride diffusion and resistivity. The durability and strength test results during the period from 28 to 90 days are presented to compare the effects of using CPF with those of traditional (plywood) formwork on OPC and PFA concrete mixes, as specified on actual construction projects in Australia. The results indicate that CPF gave improved performance compared to the traditional formwork for surface properties of concrete. However, the effects are minimal on the bulk properties of the concrete.

The site exposure of concrete cast using controlled permeability formwork

Abstract This paper presents a study to assess the effects of site exposure on the durability of concrete cast with ordinary Portland cement (OPC), pulverised fly ash (PFA) and ground granulated blast furnace slag (GGBS) using the controlled permeability formwork (CPF). An experimental program has been undertaken in which trial specimens have been placed on exposure sites at coastal locations in Australia. Various non-destructive tests were conducted such as Schmidt hammer, water permeability, air permeability, ultrasonic pulse velocity, steel potential mapping, linear polarisation resistance corrosion rate monitoring, chloride diffusion, accelerated chloride diffusion, and resistivity. The durability data are presented to compare the effects of using CPF with those of traditional (plywood) formwork for OPC, PFA and GGBS concrete mixes, as specified on actual construction projects in Australia. The results indicate that CPF gave improved performance compared to the traditional formwork for surface properties of concrete.

Optimization of passive piezoelectric vibration shunt control based on strain energy transfer and online frequency detection

Passive vibration shunt control using piezoelectric material (PZT) and an electrical network can remove considerable amount of vibration energy from flexible structures. In this paper, an analytical study of parallel passive resistor-inductor (R-L) piezoelectric vibration shunt control on a beam structure by using the Hamiltons principle, Galerkins method is presented. However, the efficiency of such vibration control method relies on the optimization of vibration energy transfer between a structure and piezoelectric material. In this paper, the strain energy transfer within the composite material, which is made of two layers of different materials, is analyzed. It indicates that neutral axis of the composite material has some influence on the optimization of the strain energy transfer between the structure and PZT. The passive vibration shunt control is sensitive to frequency shift of structures. However, in reality, the natural frequencies of flexible structures often vary somewhat due to environment change, such as boundary conditions, temperature variation, etc. The effectiveness of the vibration shunt control will be significantly reduced when the frequency of the shunt circuit does not match the natural frequency of the structure. In this paper, a method of estimating the resonant frequencies of structures using adaptive IIR notch filter is presented. With online frequency detection, the inductor value is possible to be adjusted in real time by some kind of controllable capacitors and resistors to track the frequency change of structures.

Suitability of Brown Coal Fly Ash for Geopolymer Production

AbstractThe use of low-calcium Class F fly ash both as a replacement material for cement and to produce geopolymers has become established practice. However, much of the fly ash produced globally i...

Long-term performance of controlled permeability formwork

Abstract Controlled Permeability Formwork (CPF) has been shown to improve the durability of concrete by reducing the porosity of the cover concrete. However, research to date has focused on laboratory and short-term trials. This paper reports a long-term project in which specimens have been placed on exposure sites at three coastal locations in Australia for 5 years. The specimens include three materials, 100% Portland cement, 30% Pulverised Fly Ash and 65% Ground Granulated Blastfurnace Slag. Specimens were cured using traditional plywood formwork under wet hessian for 1 and 14 days and with CPF for 1, 7 and 14 days. The performance of the concrete was monitored at six monthly intervals by means of visual inspection, Ultrasonic Pulse velocity, resistivity and surface strength using Schmidt Hammer. At the conclusion of the 5 years, chloride ingress and the apparent chloride diffusion coefficient were determined from sample cores. The results showed that the CPF improved surface appearance and surface hardness of the concrete. In addition, chloride ingress was reduced by the application of CPF, with lifetime modelling indicating that service life expectancy could be improved by up to five times when compared to one day curing under hessian.

Piezoelectric-based vibration control optimization in nonlinear wood and composite structures

Vibration control has been a subject of engineering research for the past few decades. Recently, the use of smart material-related components for vibration control has become an alternative to traditional vibration control techniques. Vibration control using such components has many advantages such as lighter overall weight and lower cost. They are especially suitable where traditional techniques cannot be applied due to weight and size restrictions. Passive vibration shunt control using piezoelectric ceramics (PZT) and an electrical network has been studied by many researchers both analytically and experimentally. In this paper, the modeling of a passive vibration shunt control on a cantilever beam using a finite element analysis software package -- ANSYS is presented. It is a useful alternative to an experimental approach that is costly as the PZT is useable only once in most instances. The simulation shows that the electrical shunt circuit can remove considerable vibration-based energy when properly tuned. The simulation reveals that the material property of the structure has a significant impact on the effectiveness of the vibration shunt circuit. This is postulated to be because of the mechanical impedance match between the structure and PZT transducer. The method provides a useful mechanism for selecting the material properties of a structure so that its vibration can be effectively absorbed by a piezoelectric vibration shunt network. Also shown in this paper is experimental verification of the computational results. This procedure has the potential for greatly increasing the flexibility in the design of such Mechatronic control devices especially when the mechanical and physical properties of synthetic materials such as polymeric composite materials can be varied to suit the application.

Cricket bats: Some performance and vibration control issues

This paper will address some of the issues in an on‐going research project involving the performance optimization and vibration control of Cricket bats. In many ways, the rules of the game have made our task a little easier by restricting exactly what we can modify in order to improve performance. For example, the blade or the hitting proportion of the Cricket bat has to remain as wood but its geometry can be altered to fit within a volume‐based specification. The handles specification, however, is not specified. Hence by our interpretation of the rules of the game, this lack of specificity for the handle in the rules provides an opportunity to improve the performance of the Cricket bat as a whole by making material and geometric modifications to the handle. This paper will address the investigation of bat performance from a dynamics and vibration analyses perspective. This paper will report on parameters such as bat–ball contact time and translation, clustering of distal node points (DNPs) to mimic an enhanced sweet spot. Results showing performance comparisons between traditional and composite material‐handle bats will be presented along with computational and analytical results for various handle shapes.This paper will address some of the issues in an on‐going research project involving the performance optimization and vibration control of Cricket bats. In many ways, the rules of the game have made our task a little easier by restricting exactly what we can modify in order to improve performance. For example, the blade or the hitting proportion of the Cricket bat has to remain as wood but its geometry can be altered to fit within a volume‐based specification. The handles specification, however, is not specified. Hence by our interpretation of the rules of the game, this lack of specificity for the handle in the rules provides an opportunity to improve the performance of the Cricket bat as a whole by making material and geometric modifications to the handle. This paper will address the investigation of bat performance from a dynamics and vibration analyses perspective. This paper will report on parameters such as bat–ball contact time and translation, clustering of distal node points (DNPs) to mimic an en...