Papers by Author: Zhong Xiao Peng

Abstract: One of the key elements of servicing the aviation industry is the provision and maintenance of first class equipment. In order to ensure a secure and effective flight of aircrafts in aviation, the ground supporting equipment which enables the planes to get off the ground without delaying the flight plans, has to be kept ready at all times [1].

Abstract: This work aimed to establish a suitable procedure for establishing wear particle hardness and to investigate if the hardness of articular cartilage wear particles increases with increasing grades of osteoarthritis. To achieve the goals a selection of fresh sheep knee joints were obtained and consequently worn in a specially designed wear simulator. Wear particles were then removed from the joint using a syringe and prepared for hardness testing. In order to test the hardness of the wear particle samples nanoindentation was used. Once completed statistical analyses and correlation analyses were performed in order to find any relationships present. This was the first time that the hardness of the wear particles was tested and studied. As a result of the tests performed a general relationship between wear particle hardness and osteoarthritis grade was able to be determined. It was also determined that further work needed to be conducted on the experimental procedure to increase the accuracy of the results obtained.

Abstract: Bone biopsy is a common procedure in bone disease diagnoses, therapies and research. In this procedure, bone biopsy needles are inserted into bone tissues. Although needle insertion into bone is often essential for the diagnosis of bone diseases, the hard tissue-needle interactions are not quantitatively understood. In this paper, we describe a quantitative assessment of forces involved in insertion of healthy trabecular bone using clinically applied Jamshidi CrownTM bone biopsy needles of gauge 8 (4-mm diameter). The measured forces were related to the insertion depths up to 25 mm and insertion rates of 1 mm/s to 5 mm/s. At the initial insertion stage, a clear linear force-depth relation was measured. With the increase of the insertion depth, the forces increased nonlinearly. In the final stage of insertion, the forces increased much more quickly at the lower insertion rate than that at the higher insertion rate. The maximum insertion force reached approximately 1000 N when the insertion depth reached 25 mm at the insertion rate of 1 mm/s.

Abstract: Dental ceramics are attractive in restorative dentistry due to their approximations to the appearances and functions of human teeth with which we chew our food. Chewing processes generally occur at cyclic loading range of 70–800 N and up to 1400 cycles per day. Most fatigue studies on dental ceramics were conducted at the loads up to 250 N. These loads are much smaller than the maximum bite forces of 500–700 N and tooth clench or grinding forces of up to 800 N. This paper reports on an investigation of fatigue response of a dental porcelain at the higher end of the load range impacted by a tungsten carbide ball. The responses of surface roughness and contact stress to the applied loads and cyclic numbers were quantitatively studied. The results show that the cyclic numbers had significant influences on both average surface roughness Ra and maximum roughness Rmax (ANOVA, p<0.05). However, the applied loads did not significantly affect Ra and Rmax values (ANOVA, p>0.05). It is also found that the contact stress significantly reduced with the cycles (ANOVA, p<0.05) but did not show a significant change with the applied loads (ANOVA, p>0.05).

Abstract: Quantitative surface measurement is an important field in many applications including materials science and engineering quality control. A non-destructive and versatile technique for quantifying surface roughness in 3D is Confocal Laser Scanning Microscopy (CLSM). However, this technique has not been widely accepted to use for quantitative surface measurements due to limited work on it. The project has researched the suitability of using the system for surface characterization and appropriate settings for image acquisition for quantitative surface analysis. Based on the above fundamental work, this study has developed and presented a comprehensive approach of using the system for quantitative surface characterization through image processing, 3D image construction, image stitching and numerical image analysis. The surface characterization results presented in the paper have demonstrated that the system can be used to accurately measure surface roughness of engineering surfaces.

Abstract: Wear is often of definite influence in the service life of mechanical components and has been recognised as one of the major causes of failure in engineering practice. It is noted that although extensive attention has been paid to phenomenological studies like surface morphology analysis for wear assessment, the physical mechanism of wear particle formation remains unclear. This paper proposes a micro damage and fracture model to simulate the process of wear particle generation. An explicit finite element (FE) formulation is employed to capture the nonlinearities involved. Unlike existing FE analysis (FEA), any initial sub-fractures underlying the wear surface are no longer required. Crack initiation and propagation as well as the corresponding mesh updating are implemented in an automatic fashion associated with the explicit FE framework. The results presented are in good agreement with experimental observation and the reports in existing literature.