Engineering Commons^™

Experimental Investigation Of Welding Stresses In Mwic Weldability Test, Houman Alipooramirabad, Anna Paradowska, Reza Ghomashchi, Nicholas P. Hoye, Mark H. Reid

Faculty of Engineering and Information Sciences - Papers: Part A

The use of high-strength steels in the manufacture of energy pipelines, coupled with the transition to larger pipe diameters and greater wall thicknesses, has led to an increased potential for cracking including hydrogen assisted cracking of energy pipelines due to higher constraint induced stresses. In the present study, a modified version of the Welding Institute of Canada (MWIC) restraint test was used to simulate the constraint conditions of full-scale girth welds on energy pipelines, allowing the influence of welding process parameters on crack formation to be assessed. MWIC test samples of X70 grade high-strength low alloy pipeline steel were manually …

Residual Stress And Critical Crack Size Before And After Post-Weld Heat-Treatment, M Law, Anna Paradowska, Nicholas P. Hoye, P Grace

Faculty of Engineering and Information Sciences - Papers: Part A

Post-weld heat-treatment (PWHT) is performed to reduce residual stress, but is not always possible to perform. The residual stresses on a thick section weld on a gas pipeline were determined before and after PWHT to assess residual stress and critical defect sizes.

Residual Stress Study Of Al/Al Laminates Processed By Accumulative Roll Bonding, Lihong Su, Cheng Lu, Hui Jun Li, Vladimir Luzin, Hui Wang, Anh Kiet Tieu

Faculty of Engineering and Information Sciences - Papers: Part A

In this work accumulative roll bonding (ARB) was used to combine AA1050 and AA6061 sheets to produce AA1050/AA1050, AA6061/AA6061 and AA1050/AA6061 laminates with ultrafine grained (UFG) structure. Two sheets of starting materials were roll bonded with 200 °C preheating for 180 s before rolling. The through-thickness residual stress distribution of these laminates processed up to two cycles of ARB was determined by neutron diffraction with spatial resolution of 0.2 mm through 1.5 mm thickness. The measurements also required high accuracy of only few MPa since residual stresses in the laminates peaked at only about 15 MPa. The laminates composed of …

An Active Seat Suspension Design For Vibration Control Of Heavy-Duty Vehicles, Donghong Ning, Shuaishuai Sun, Jiawei Zhang, Haiping Du, Weihua Li, Xu Wang

Faculty of Engineering and Information Sciences - Papers: Part A

This paper presents the design, fabrication and testing of an innovative active seat suspension system for heavy-duty vehicles. Rather than using conventional linear actuators, such as hydraulic cylinders or linear motors, which need to be well maintained and are always expensive when high force outputs are required, the proposed seat suspension system directly applies a rotary motor in order to provide the required active actuation, without changing the basic structure of the existing off-the-shelf seat suspension. A gear reducer is also applied to amplify the output torque of the motor so that a high output torque can be achieved using …

Visualisation For Large-Scale Gaussian Updates, Jonathon Rougier, Andrew Zammit-Mangion

Faculty of Engineering and Information Sciences - Papers: Part A

In geostatistics and also in other applications in science and engineering, it is now common to perform updates on Gaussian process models with many thousands or even millions of components. These large-scale inferences involve modelling, representational and computational challenges. We describe a visualization tool for large-scale Gaussian updates, the 'medal plot'. The medal plot shows the updated uncertainty at each observation location and also summarizes the sharing of information across observations, as a proxy for the sharing of information across the state vector (or latent process). As such, it reflects characteristics of both the observations and the statistical model.We illustrate …

Kinematical Limit Analysis For A Slope Reinforced With One Row Of Stabilizing Piles, Shiguo Xiao, Hong He, Jinxiu Zeng

Faculty of Engineering and Information Sciences - Papers: Part A

Stabilizing piles are commonly used to improve slope stability. The load that a pile should sustain and the associated slip surface under a prescribed factor of safety are two critical design parameters in practice. Based on the kinematically admissible failure mechanism, a limit analysis approach is introduced, which considers two potential slip surfaces that individually lie in the upslope and downslope of the piles. The explicit formulas for the upslope thrust force and downslope resistance on a pile are derived, which enables the calculation of the maximum load on a pile and the corresponding critical slip surfaces using a computer …

Evaluation Methodology And Implementation For Natural Ventilation Control Strategies, Massimo Fiorentini, Georgios Kokogiannakis, Warwick Jackson, Zhenjun Ma, Paul Cooper

Faculty of Engineering and Information Sciences - Papers: Part A

This paper describes a methodology for evaluating the effectiveness of various control strategies for the operation of window actuators to control the indoor climate, and their implementation in a full scale case study building. In this study, the effectiveness of a control strategy is considered in terms of the capability of the controller for maintaining the indoor thermal comfort in a prescribed variable range, and its effect on the minimisation of the operational energy consumption of the building, due to a lower thermal energy demand to be met by the heating and cooling system. A model of the case study …

Building Characterisation And Retrofit Decision Support-Tools For Upgrading Homes Of Low-Income Older Australians, Paul Cooper, Clayton Mcdowell, Michael P. Tibbs, Georgios Kokogiannakis, Laia Ledo Gomis, Stephen C. Choi

Faculty of Engineering and Information Sciences - Papers: Part A

This paper describes the development and implementation of a comprehensive methodology to select and implement energy efficiency upgrades to the homes of low-income, older (>60 years) Australians. This work was conducted as part of a project entitled, 'Energy Efficiency in the 3rd Age (EE3A)", which targeted lowincome older residents in the Illawarra Region of NSW, Australia, and was funded by an Australian Federal Government 'Low Income Energy Efficiency Program (LIEEP)' grant for AUD2.3M. The project included a social marketing and behaviour change component engaging ~650 households, and a retrofit program for a subset of ~183 of these homes. Households …

Development Of A Novel Magnetophoresis-Assisted Hydrophoresis Microdevice For Rapid Particle Ordering, Sheng Yan, Jun Zhang, Huaying Chen, Dan Yuan, Gursel Alici, Haiping Du, Yonggang Zhu, Weihua Li

Faculty of Engineering and Information Sciences - Papers: Part A

Focusing and ordering of micro- or nanoparticles is an essential ability in microfluidic platforms for bio-sample processing. Hydrophoresis is an effective method utilising hydrodynamic force to focus microparticles, but it is limited by the fixed operational range and the lack of flexibility. Here, we report a work to tune and improve the dynamic range of hydrophoresis device using magnetophoresis. In this work, a novel approach was presented to fabricate the lateral fluidic ports, which allow the flipped chip to remain stable on the stage of microscope. Diamagnetic polystyrene microparticles suspended in a ferrofluidic medium were repelled to the lower level …

Optimization Of A Ceiling Ventilation System With Integrated Photovoltaic Thermal Collectors And Phase Change Materials, Zhenjun Ma, Wenye Lin, Mohammed I. Sohel

Faculty of Engineering and Information Sciences - Papers: Part A

This paper presents the performance evaluation and design optimization of a ceiling ventilation system with integrated solar photovoltaic thermal (PVT) collectors and phase change materials (PCMs) by using a hybrid Particle Swarm Optimization and Hooke-Jeeves Pattern search (PSO-HJ) algorithm. In this novel ceiling ventilation system, the PVT collectors are used to generate electricity and provide the low-grade heating energy for buildings by using the winter daytime solar radiation, while the PCM is integrated into the building ceiling as part of the ceiling insulation and at the same time, as a centralized thermal energy storage unit to temporally store the low-grade …

Balance Improvement Effects Of Biofeedback Systems With State-Of-The-Art Wearable Sensors: A Systematic Review, Christina Ma, Duo Wong, Wing K. Lam, Anson Wan, Winson Lee

Faculty of Engineering and Information Sciences - Papers: Part A

Falls and fall-induced injuries are major global public health problems. Balance and gait disorders have been the second leading cause of falls. Inertial motion sensors and force sensors have been widely used to monitor both static and dynamic balance performance. Based on the detected performance, instant visual, auditory, electrotactile and vibrotactile biofeedback could be provided to augment the somatosensory input and enhance balance control. This review aims to synthesize the research examining the effect of biofeedback systems, with wearable inertial motion sensors and force sensors, on balance performance. Randomized and non-randomized clinical trials were included in this review. All studies …

Wearable Vibrotactile Biofeedback Device Allowing Identification Of Different Floor Conditions For Lower-Limb Amputees, Anson Wan, Duo Wong, Christina Ma, Ming Zhang, Winson Lee

Faculty of Engineering and Information Sciences - Papers: Part A

Objective

To evaluate a newly developed biofeedback device enabling lower-limb amputees to identify various floor conditions.

Design

Self-control with repeated measures (with and without the biofeedback device) within the amputee group, and group control comparing between amputee and nonamputee groups.

Setting

University locomotion laboratory.

Participants

Five lower-limb amputees and 8 nonamputees (N=13).

Interventions

A wearable biofeedback device, which identified different floor conditions by analyzing the force patterns under the prosthetic feet and provided vibration cues in response to different floor conditions, was provided to the amputees.

Main Outcome Measures

The subjects stepped on a foam platform concealing a small object …