Thesis (M.Sc.)--University of the Witwatersrand, Faculty of Engineering, 1996 / One of the major impediments in the field of numerical modelling in rock mechanics is limited knowledge of the mechanisms of fracture and failure of brittle rock. One important tool for improving the understanding of rock behaviour is the use of laboratory experiments under controlled conditions. The Displacement Discontinuity Method, capable of fracture growth simulation (DIGS), has been used to model fracturing in samples under punch loading. A Finite Difference Method, capable of plastic deformations due to its explicit time marching scheme (FLAC), has also been used to model the punch tests. By comparing numerical simulations with results from laboratory experiments of punch tests, it has been possible to define the basic failure mechanism for pillar foundation failure. Two different test set-ups were used namely, steel jacketed axisymmetric punch tests and long strip punch tests in the triaxial cell which is built for these specific tests. The layered structure of the test specimens and in the test procedure had significant effects on the fracture pattern as well as the failure load. When the layer is near to the punch area, then both the layer and the layer conditions had a strong effect on the failure load. When the layer was frictionless, the failure stress dropped by about 20 percent. The same result occurred in both the axisymmetry and strip loading tests. When shear fractures intersect a layer with either low or high friction it terminates. This is not the case for the tensile fractures, which can pass through the layer media. However, it is important to note that the tensile fractures which originate from near the cone area can not pass through the layers. They stop at the interface.

by Yeung Ming San, Josephine. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1992. / Includes bibliographical references (leaves 161-172). / ABSTRACT --- p.1 / Chapter I. --- INTRODUCTION --- p.4 / Chapter II. --- LITERATURE REVIEW --- p.12 / Chapter 2.1 --- Functional Anatomy of Ankle and Subtalar Joint --- p.12 / Chapter 2.1.1 --- Bony Configuration --- p.12 / Chapter 2.1.2 --- Axis of Motion --- p.13 / Chapter 2.1.3 --- Lateral Ligaments --- p.13 / Chapter 2.1.4 --- Ankle Musculature --- p.13 / Chapter 2.2 --- Biomechanics of Ankle Ligaments --- p.14 / Chapter 2.2.1 --- Characteristics of Lateral Ligaments of the Ankle --- p.15 / Chapter 2.2.1.1 --- Ligaments for Stability --- p.15 / Chapter 2.2.1.2 --- Ligaments Properties to Loading --- p.15 / Chapter 2.3 --- Lateral Ankle Ligaments Injuries --- p.17 / Chapter 2.3.1 --- Etiology --- p.17 / Chapter 2.3.2 --- Definition of Sprain --- p.18 / Chapter 2.3.3 --- Classification of Inversion Ankle Sprain --- p.18 / Chapter 2.3.4 --- Diagnosis of Lateral Ligaments Injury --- p.19 / Chapter 2.3.4.1 --- Anterior Draw Test --- p.19 / Chapter 2.3.4.2 --- Talar Tilt Test --- p.21 / Chapter 2.3.4.3 --- Anthrogram --- p.21 / Chapter 2.3.4.4 --- Controversies in Various Diagnostic Methods for Lateral Ankle Ligaments Injury --- p.21 / Chapter 2.3.5 --- Orthopedic Management of Inversion Ankle Sprain --- p.22 / Chapter 2.3.5.1 --- Operative Method --- p.22 / Chapter 2.3.5.2 --- Conservative Method --- p.23 / Chapter 2.4 --- Rehabilitation of Inversion Ankle Injury --- p.24 / Chapter 2.4.1 --- Residual Problems Resulted from Inversion Ankle Injury --- p.24 / Chapter 2.4.1.1 --- Epidemiology --- p.24 / Chapter 2.4.1.2 --- Muscle Weakness --- p.25 / Chapter 2.4.1.3 --- Proprioception --- p.27 / Chapter 2.4.1.4 --- Peroneal Muscle Reaction Time --- p.29 / Chapter 2.4.1.5 --- Muscle Tightness --- p.30 / Chapter 2.4.2 --- Rehabilitation Training --- p.31 / Chapter 2.4.2.1 --- Muscle Training --- p.31 / Chapter 2.4.2.2 --- Proprioception Training --- p.32 / Chapter 2.4.2.3 --- Other Training --- p.32 / Chapter 2.5 --- Strength Training --- p.33 / Chapter 2.5.1 --- Effects of Strength Training --- p.33 / Chapter 2.5.1.1 --- On Muscle --- p.33 / Chapter 2.5.1.2 --- On Nervous System --- p.33 / Chapter 2.5.1.3 --- On Ligaments --- p.34 / Chapter 2.5.2 --- Isokinetic Training --- p.34 / Chapter III. --- METHODOLOGY --- p.39 / Chapter 3.1 --- Epidemiological Survey --- p.42 / Chapter 3.1.1 --- Design of Questionnaire --- p.42 / Chapter 3.1.2 --- Pilot Study --- p.43 / Chapter 3.1.3 --- Survey --- p.44 / Chapter 3.2 --- Isokinetic Evaluation for Normal Non-injured Ankle --- p.45 / Chapter 3.2.1 --- Subjects --- p.45 / Chapter 3.2.2 --- Equipment --- p.46 / Chapter 3.2.3 --- Testing Procedure --- p.51 / Chapter 3.3 --- Evaluation for Ankle with Inversion Sprain --- p.59 / Chapter 3.3.1 --- Initial Evaluation --- p.60 / Chapter 3.3.1.1 --- Criteria for Subjects --- p.60 / Chapter 3.3.1.2 --- Interview of Subjects --- p.61 / Chapter 3.3.1.3 --- Testing Procedure --- p.61 / Chapter 3.3.2 --- Training Program --- p.66 / Chapter 3.3.2.1 --- Subjects --- p.66 / Chapter 3.3.2.2 --- Various Methods of Training or Exercise --- p.67 / Chapter 3.3.2.3 --- Isokinetic Exercise Protocol for Ankle --- p.69 / Chapter 3.3.2.4 --- Design of Training Protocol --- p.71 / Chapter 3.3.3 --- Second Evaluation --- p.73 / Chapter 3.3.3.1 --- Subject --- p.73 / Chapter 3.3.3.2 --- The Retest --- p.73 / Chapter 3.4 --- Data Analysis --- p.74 / Chapter IV. --- RESULTS --- p.75 / Chapter 4.1 --- Epidemiological Study --- p.75 / Chapter 4.1.1 --- Athletes' Personal Data --- p.75 / Chapter 4.1.2 --- Athletes' Injury Data --- p.82 / Chapter 4.1.3 --- Residual Problems in Ankle Sprains --- p.84 / Chapter 4.2 --- Isokinetic Evaluation for Normal Non-injured Ankle --- p.89 / Chapter 4.2.1 --- Subjects Data --- p.89 / Chapter 4.2.2 --- Range of Active and Passive Ankle Dorsiflexion --- p.89 / Chapter 4.2.3 --- Muscular Parameters Used for Data Analyzing --- p.90 / Chapter 4.2.4 --- Comparing Muscular Parameters between Dominant and Non-dominant Ankle of Normal Subjects --- p.90 / Chapter 4.2.5 --- Comparing Muscular Parameters between Male and Female Normal Subjects --- p.94 / Chapter 4.2.6 --- Torque Ratio and Work Ratio --- p.98 / Chapter 4.3 --- Evaluation for Ankles with Inversion Sprain --- p.102 / Chapter 4.3.1 --- Initial Evaluation --- p.102 / Chapter 4.3.1.1 --- Subjects Data --- p.102 / Chapter 4.3.1.2 --- Anterior Draw Sign --- p.103 / Chapter 4.3.1.3 --- Range of Motion --- p.103 / Chapter 4.3.1.4 --- Ankle Functional Rating Scale --- p.104 / Chapter 4.3.1.5 --- Isokinetic Evaluation --- p.104 / Chapter 4.3.2 --- Second Evaluation --- p.116 / Chapter 4.3.2.1 --- Subjects Data --- p.116 / Chapter 4.3.2.2 --- Comparing the Initial and Second Evaluation Ankle Functional Rating Scale --- p.117 / Chapter 4.3.2.3 --- Comparing Initial and Second Evaluation for Isokinetic Parameters of the Ankle --- p.118 / Chapter 4.3.3 --- Correlation of Various Isokinetic Parameters of the Ankle with Ankle Functional Rating Score --- p.124 / Chapter V. --- DISCUSSION --- p.127 / Chapter 5.1 --- Epidemiological Study --- p.127 / Chapter 5.2 --- Evaluation for Normal Non-injured Ankle --- p.132 / Chapter 5.3 --- Evaluation for Ankle with Inversion Sprain --- p.141 / Chapter 5.4 --- Isokinetic Rehabilitation --- p.148 / Chapter 5.5 --- Limitations and Future Direction of Research --- p.153 / Chapter VI. --- CONCLUSION --- p.156 / Chapter VII. --- REFERENCE --- p.161 / APPENDIX I --- p.i / APPENDIX II --- p.vi / APPENDIX III --- p.viii / APPENDIX IV --- p.xiii

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In this thesis work, a novel low level birefringence detection (LLBD) system operating at 1150 nm was set up based on the photoelastic modulation techniques. The noise level of current LLBD system is about 0.03° and the maximum fluctuation of data in ten measurements is 0.05° and close to the noise level of system. With a slit confining the light, the spatial resolution of the system is 10 mum. Optical orientation and retardation can be simultaneously measured by this system, making the stress measurement more convenience than the traditional PE methods. These peculiar features make this system capable of investigating the details of stress distribution in semiconductor structures. / Our solution reveals that the nonlinear stress filed is responsible for the shift of the zero stress point. Further it is indicated that the classical Stoney formula can either overestimate or underestimate the actual film stress due to the process induced nonlinear stress in the substrate. / Stress and strain play an essential role in determining the structural, electrical, and optical properties of semiconductor materials, and, ultimately, the semiconductor device performance. Many methods have been utilized to measure the stress in semiconductors. Among them infrared photoelasticity method is a promising one, which can be used both in the industrial characterization and scientific research. This thesis is an endeavor in this subject matter and will present our research results of studying the stress problems in semiconductor structures by using infrared photoelasticity method. / The LLBD system was applied to measure the stress distributions in the substrates of SiO2/Si structure. Some deviations from the classical film theory were observed in our experiments. For example non-linear stress fields were observed in all samples whatever their process conditions are. Besides the locations of neutral axis (zero stress point) was not located at the depth of 2/3 thickness of the substrate from the interface as expected by the bi-metallic theory. To interpret these deviations, a theoretical analysis was given to investigate the problem of stress distribution in film/substrate structure. A series of solutions were deduced to modify the Stoney formula and bi-metallic strip theory with the consideration of the nonlinear stress in substrate. / by Liu Xianghua. / "Feb 2006." / Adviser: Sai Peng Wong. / Source: Dissertation Abstracts International, Volume: 67-11, Section: B, page: 6674. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

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In arid end semiarid areas in the Western United States, soluble salts tend to accumulate in the soil in amounts harmful to crop production. A considerable portion of this land cannot be reclaimed due to the poor quality of permeability of the soil o Therefore, the wise selection of crops that will produce satisfactory yields on these soils in necessary.

Knowledge of the stress-strain relationship of the compacted soils in tension is of importance for understanding of cracking that occurs in earth structures, in particular embankment dams and landfill barriers. Understanding the correlation between tensile properties and traditional soil parameters and soil suction is essential in identifying problems associated with desiccation induced cracking. A series of extensive laboratory experiments were performed on three different soils from existing embankment dams. This thesis concentrated on the investigation of tensile strength in relation to the type of soil, compaction water content, compaction density ratio, rate of loading, soil suction, moisture retention characteristics and the effect of drying and wetting. Stress-strain behaviour and tensile properties indicated a dependence on soil type and compaction criteria. The plasticity index, clay content and type of mineral has shown a significant influence on tensile strength. Compaction dry of optimum resulted in an increase in strength. Compaction wet of optimum showed a decrease in strength and small increase in strain at failure. Higher compaction effort resulted in higher tensile strength, tensile stiffness and brittle stress-strain behaviour. Difference in loading rate revealed response time for initial tensile deformation as well as sustainable duration up to failure point. The effect of soil suction plays an important role in drying during which specimens exhibited a considerable strength increase. The magnitude of strength increase may have been contributed by a combination of suction, air entry value and compaction density. The effect of wetting could cause decreasing in suction and thus a reduction in strength. Based on the findings, it was concluded that the desiccation-induced may not necessarily occur due to an associated increase in tensile strength. However, an increase in tensile strength is likely to be accompanied by an increase in shrinkage. Therefore, desiccation-induced cracking is related to the interaction between moisture loss, change in soil suction, tensile stress and shrinkage.

Interbody fusion cages are increasingly used in the treatment of spinal disease and injury in order to stabilize movement and promote arthrodesis of the vertebral bodies, but the micro-mechanics of the interaction between the cage and the adjacent host bone is not fully understood. This information has bearing on post-surgical therapy protocols, prediction of long-term bone tissue changes, and optimization of cage design. In order to gain insight into this problem, functional microCT imaging was used to directly evaluate implant micromotion and full-field vertebral body strains in an animal model implemented with various configurations of BAK interbody cages. It is believed that variations in cage design will produce variable implant success, functional fusion will be related to the extent of implant fixation, and specific strain fields will be associated with fused and unfused samples. We found that samples ranged from completely unfused (implant motion) to fully fused with organized trabecular bone (no motion). Strains concentrated at the implant interface in unfused samples, while fully fused samples exhibited uniformly distributed strains. / Graduation date: 2004

Thesis (M.Eng.)--Memorial University of Newfoundland, 2005. / Bibliography: leaves 113-116.