FEA simulation of contact and wear between non-metallic materials for accelerated new product development

The conventional approach ie laboratory life testing to examine the reliability of products takes long time and involves tremendous cost as samples are tested till failures. The accelerated life test (ALT) has recently been used as an alternative method. Although ALT reduces the cost of reliability testing through applying more severe environmental conditions than the normal ones, it is no longer sufficient as it does not describe the process of products’ failure explicitly and it is still highly dependent on physical testing. Consequently, novel practices need to be developed for better understanding of the products’ reliability. A novel Finite Element Analysis (FEA) model incorporating mathematical wear equations is developed in the current work and applied to polymer materials. Wear rate, a key parameter, is calculated by using a combinatorial formula that combines a conventional linear equation with a recently published exponential equation. The local wear is firstly calculated and then integrated over the sliding distance. The FEA simulation works in a loop and performs a series of simulation with updated surface geometries. The simulation is in good agreement with the physical testing result.

Investigation of processing conditions of melded parts to determine process boundaries

Melding, a novel method for producing seamless joints in thermosetting composites utilising the Quickstep™ process, is explored in this paper. The effect of processing conditions on the quality of melded joins is examined and a set of processing boundaries defined so that the strength of melded joints is optimized. HexPly® 914c pre-preg material was exposed to a range of processing temperatures prior to joining via the melding process. Differential Scanning Calorimetry analysis was carried out to investigate the degree of cure of material prior to final joining, and it was found that minimal cure occurs at temperatures below 120°C. After consolidation and cure of the melded parts, short beam shear testing was conducted to evaluate the strength of the melded interface. Exposure temperatures between 65°C and 120°C were found to optimize short beam shear join strength. Mode I double cantilever beam and mode II end notched flexural tests showed no detrimental effect of elevated exposure temperatures prior to joining.

Modeling of contact pressure in sheet metal forming

For a given sheet metal forming process, an accurate determination of the contact pressure distribution experienced is an essential step towards the estimation of tool life. This investigation utilizes finite element (FE) analysis to determine the evolution and distribution of contact pressure over the die radius, throughout the duration of a channel forming process. It was found that a typical two-peak steady-state contact pressure response exists for the majority of the process. However, this was preceded by a transient  response, which produced extremely large and localized contact pressures. Notably, it was found that the peak transient contact pressure was more than double the steady-state peak. These contact pressure results may have a significant influence on the tool wear response and therefore impact current wear testing and prediction techniques. Hence, an investigation into the validity of the predicted contact pressure was conducted.

Healthy parks, healthy people : the health benefits of contact with nature in a park context : a review of current literature

This review identifies significant research that has not previously been compiled. It will provide key information for decision making by park managers, forming the basis of a program of future research to overcome the limited knowledge in this area. It is part of stage two of this project, funded by the International Park Strategic Partners Group. It builds on an earlier review (completed early in 2002 with funding provided by Parks Victoria) by addressing the health and wellbeing benefits of contact with nature in a parks context, at an individual and community level.

The use of artificial biofilms to strip nutrients from an industrial smelters waste water under conditions of low temperature and high pH

The Victorian Environment Protection Authority (EPA) has identified Alcoa’s Point Henry aluminium smelter as being a major source of recognized pollutant input due to its disposal of effluent into Corio Bay. Historically, the water quality parameters that have most often exceeded Point Henry’s EPA limits have been pH and suspended solids from the smelter’s discharge points. These waste water discharges also experience high nitrogen and phosphorus concentrations which result in algal blooms that occur at the onset of warm weather. The main hypothesis of this study was that “prevention of algal blooming with the onset of warm weather by removal of nutrients during the cooler months, and continued removal thereafter, is better than curing the problems chemically”. Biofilms have been used to remove nutrients from waste waters, but not under the conditions experienced at Point Henry. The aim of this study, therefore, was to determine if significant biofilm growth would be observed on floating structures suspended in the Point Henry waste water stream during the cooler, winter months of the year. Statistically significant biofilm growth occurred on all suspended structures in all discharge ponds during the winter and early spring of 2000. The use of suspended structures, such as AquaMatTM, as an artificial substrate to attract and support periphyton and bacterial communities (biofilms), which are then able to out-compete phytoplankton communities for available nutrients, is therefore a viable option for the Point Henry smelter. However, further research on the competitive performance of biofilms in the Point Henry ponds during the summer months is required before adequate biofilm management strategies can be developed.

Perceived conditions of workers in different organizational settings

Purpose: – Research into office design and its effect on employee satisfaction and performance has attracted considerable contemporary research interest. However, most studies have tended to concentrate on the impact of the built environment on human performance, ignoring the actual needs of employees working in different organizational settings. This paper hence aims to investigate the nature and extent of occupant satisfaction with the built environment in different organizational settings in Australia for a range of climates.

Design/methodology/approach: – A survey was conducted in Australia from 2004-2005, comprising 41 buildings, including six government buildings, 14 educational buildings and 21 commercial buildings. The Kruskal-Wallis H test was used to explore whether there are differences in the mean ranking of office environment satisfaction amongst the three organizational settings, and the Mann-Whitney U test was employed to further test whether there are differences in the mean ranking of office environment satisfaction between any two groups.

Findings: – Significant differences were found in aspects of air, temperature, space suitability, flexibility, usability and controllability. Employees in commercial settings seem to be more satisfied with their physical work environment than employees in other organization types. Employees in educational settings showed the highest satisfaction with most variables in the workspace design and management category. Government employees showed a lower level of satisfaction with their physical work environment and workspace design and management.

Originality/value: – Moreover, the government and educational groups showed more similarity with each other, while the commercial group displayed significant difference.

Simulation of contact pressure in sheet metal trimming/blanking process

In the car body stamping process, trim/blank die cutting edges are subjected to very high tribological loads that result in loss of tool material from both the punch and die cutting edges. According to Archard’s wear model, normal contact force and sliding distance directly affects the wear. Therefore, knowledge of the acting forces on local contact areas has a pivotal role towards the prediction of tool wear. This paper presents a finite element modelling approach to determining the contact pressure distribution on the tool cutting edges during a trimming/blanking process. Characteristic areas on sheared edge profile, variation of punch force and high contact pressures affected areas have also been analysed.

Leading educational re-design to sustain socially just schools under conditions of instability

There is now significant evidence that school and leadership redesign is necessary in order to achieve more socially just educational futures for all students and a productive and professionally rewarding environment for teachers. Redesign requires some fundamental shifts in how schools work; engagement with and through learning communities based on systematic critical inquiry; and inclusive leadership practices that address the complexities of the relationships between diversity, culture, gender and race in schooling. I argue that democratic leadership is most conducive to initiating and sustaining equitable outcomes. The article concludes with consideration of principles that could sustain leadership for social justice.

The work conditions of allied health professionals : the impact on satisfaction, commitment and psychological distress

The present study investigated the extent to which the Demand-Control-Support (DCS) model, in combination with organizational justice variables, predicts the employee-level outcomes of allied health professionals'. Allied health professionals from an Australian healthcare organization were surveyed, with 113 participating (52,6%). Multiple regression analyses revealed that the DCS model predicted all the outcome variables of job satisfaction, organizational commitment and psychological distress. Conversely, significant contributions of the organizational justice variables were limited to organizational commitment and psychological distress. The results of the study provide practical implications for the job conditions of allied health professionals, in particular, the delivery of support and maintaining high levels of justice.

Officer wellbeing, satisfaction and commitment : job conditions of Australian law enforcement personnel

Excessive job stress caused by unreasonably high employer demands, low control over one's own work and limited support can have far-reaching effects for the individual, organisation and community. The present study sought to investigate the relationship between officer working conditions and their self-reported levels of wellbeing, satisfaction and commitment using a well-known job strss model, the demand-control-support (DCS) model. Using a large (N= 2085) sample of law enforcement personnel, findings indicated that social support from work sources was the best predictor, whilst job control and workload both had significant influences on levels of employee wellbeing, satisfaction and commitment. Additionally, non-linear relationships were found between workload and wellbeing and satisfaction, indicating that both high and low levels of workload can produce negative outcomes. The results have implications for job design and management training programs, particularly in reference to social support training and workload models.

The impact of the work conditions of allied health professionals on satisfaction, commitment and psychological distress

BACKGROUND: Allied health professionals are integral to the effective delivery of hospital-based health care, yet little is known about the working conditions associated with the attitudinal and health outcomes of these employees.

PURPOSE: The purpose of this study was to investigate the extent to which the demand-control-support model, in combination with organizational justice variables, predicts the employee-level outcomes of allied health professionals.

METHODOLOGY/APPROACH: Allied health professionals from an Australian health care organization were surveyed, with 113 (52.6%) participating. The survey included measures of job demands, job control, social support, organizational justice, satisfaction, commitment and psychological distress.

FINDINGS: Multiple regression analyses reveal that the additive demand-control-support model predicts the outcome variables of job satisfaction, organizational commitment and psychological distress, whereas the organizational justice variables predicted organizational commitment and psychological distress. Further, both work and nonwork sources of support, in addition to specific justice dimensions, were closely associated with employee-level outcomes.

PRACTICAL IMPLICATIONS: When coupled with previous research involving social support and organizational justice, the findings from this study suggest that initiatives aimed at strengthening supervisor and nonwork support, while enhancing perceptions of organizational fairness, may offer useful avenues for increasing the levels of satisfaction, commitment and well-being experienced by allied health professionals.