PRISM :: Browsing by Author "Shrive, Nigel G."

Browsing by Author "Shrive, Nigel G."

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Open Access
A new non-metallic anchorage system for post-tensioning applications using CFRP tendons
(1999) Taha, Mahmoud Reda; Shrive, Nigel G.
Open Access
A new teaching model of the systemic circulation that incorporates reservoir characteristics
(2015-02-24) Tyberg, John V.; Bouwmeester, J. C.; Burrowes, Lindsay M.; Parker, Kim H.; Shrive, Nigel G.; Wang, Jiun-Jr.
Abstract A hydraulic teaching model of the human systemic circulation is proposed, based on the principles of the reservoir-wave approach. Reservoir characteristics are portrayed by the arterial tall-and-narrow and venous short-and-wide columns, the relative compliances of which are signified by their diameters. Wave characteristics are represented by proximal arterial and venous resistances; rapid left ventricular ejection and rapid right atrial filling cause flow-dependent pressure drops across the respective resistances. (The value of the proximal arterial resistance is numerically equal to the characteristic impedance.) The pressure drop across the proximal arterial resistance, excess pressure, is understood to be fundamentally wave-related and has been shown to be a measure of the efficiency of cardiac-vascular coupling. Excess pressure also predicts an incremental risk of cardiovascular morbidity and largely accounts for the hysteresis evidenced by an open aortic pressure-volume loop.
Open Access
A six degree of freedom goniometer for the rabbit knee
(1997) Tremaine, Daren Paul; Shrive, Nigel G.
Open Access
An in vivo study of mechanical properties of wounds during healing
(2002) Zou, Jingyao; Shrive, Nigel G.
Open Access
Behavior and design of CFRP post-tensioned masonry diaphragm walls
(2001) Lissel, Shelley Lynn; Shrive, Nigel G.
Open Access
Bonding of new concrete to old concrete
(1986) Wall, James S.; Shrive, Nigel G.
Open Access
Brittle fracture in compression
(1994) Wang, Erzhuang; Shrive, Nigel G.
Open Access
Carbon fibre reinforced reactive powder concrete (CFRRPC) anchorage system
(2004) Shaheen, Ehab Abdel Hameed; Shrive, Nigel G.
Open Access
Characterization and repair of historic stone masonry structures
(2010) Sorour, Mohamed Mahmoud Labib; Shrive, Nigel G.
The 2005 National Building Code of Canada (N BCC) requires that buildings be able to resist an earthquake that can occur once every 2500 years (2% chance of exccedance in 50 years). In a project to maintain and conserve the Parliament Buildings of Canada, it was required to assess the buildings in relation to their ability to conform to the requirements of the NBCC. For older buildings like the Parliament Buildings of Canada, the code requires that such buildings be able to resist at least 60% of the forces exerted on it by the 1 in 2500 years earthquake. Therefore, it was necessary to evaluate the caracity of the buildings on Parliament Hill, and the loads that could develop in the buildings in the case of an earthquake of the expected magnitude. In order to calculate the capacity or the buildings, and the forces exerted on them by an earthquake, certain properties of the walls constituting the building should be identified like the elastic modulus and the shear modulus. This thesis focuses on determining these properties for walls representative of the West Block or the ParIiament BuiIdings, the building currently undergoing maintenance. The question was also raised as to what strengthening measures could be implemented if the walls needed such treatment, as it was expected that the unreinforced masonry walIs would not be able to survive such an earthquake. Accordingly, several potential strengthening techniques were assessed during the study. The West Block is constructed from unreinforced stone masonry walls. The walls are multiwythe with an outer face of sandstone, and an inner of limestone, surrounding a rubble core of dressed stones and mortar. Eight wall specimens representative or the walls of the West Block were built with materials similar to those used in the building. The walls were 2.75 111 high , 2 111 wide and 0.54 111 thick. Five potential strengthening techniques were applied in the walls, all being through-the-wall anchorage systems. The walls were tested in different conditions to obtain the properties sought, as well as any other information about the properties of the walls and their behaviour. The walls were tested under eccentric and concentric axial compression, shear, flexure, free vibration, slow and high frequency racking, at which push/pull lateral loading cycles were applied on the walls, and out-of-plane shake tests, where the walls were subjected to scaled earthquake signals on a shake table. The results obtained from the axial , shear and flexure tests were analyzed to obtain the properties sought. The behaviour of such walls was found to be much more complicated than originally thought. Unexpectedly, the plain walls survived all of the tests with little damage, demonstrating their robustness. None or the proposed strengthening techniques were found to make a significant difference to wall behaviour. A large amount of data was obtained from the tests that arc reported here . However, this thesis is focussed on analysing the ·'static .. results for the information or interest, and assessing the proposed strengthening techniques. The dynamic data arc analysed qualitatively, with the in-depth detailed analysis being left for future research.
Open Access
Creep behaviour and creep mechanisms of normal and healing ligaments
(2000) Thornton, Gail Marilyn; Shrive, Nigel G.
Open Access
Design and evaluation of an in vivo indentation device for articular cartilage
(1994) McPherson, Roger Wayne; Shrive, Nigel G.
Open Access
Design and implementation of a method for structural testing of knee joints
(1993) Chimich, Dennis David; Shrive, Nigel G.
Open Access
Design rules for hollow concrete masonry walls subjected to concentrated loads
(2002) Yi, Junyi; Shrive, Nigel G.
Open Access
Development of a method for robotic reproduction of in-vivo joint motion
(2004) Howard, Ryan A.; Shrive, Nigel G.
Osteoarthritis (OA) is a degenerative joint disease which has been shown frequently to follow injury of the connective tissues of the knee. In order to restore the mechanical function of the joint following such injury, a more complete understanding of joint mechanics is necessary. In this study, a system was developed for the measurement of in-vitro joint and structure loads during robotic application of in-vivo kinematics to the ovine stifle joint. In-vivo kinematics of 3 animals were measured, following which kinematics were re-applied in-vitro using a parallel manipulator. Resulting joint and structure loads were measured, and the sensitivity of these load measurements to kinematic perturbations determined. The development of this method demonstrated the importance of spatial positioning in obtaining valid load measurements. Future directions involve improvement of spatial accuracy, following which the system is expected to provide a useful tool for the estimation of in-vivo joint and structure loading.
Open Access
Dynamic in vivo kinematics in an ovine stifle joint model of osteoarthritis
(2010) Tapper, Janet Elizabeth; Shrive, Nigel G.
Open Access
Early molecular changes quantified in the ovine stifle joint two weeks post anterior cruciate ligament autograft surgery
(2011) Heard, Bryan John; Shrive, Nigel G.
Open Access
Effects of different levels of joint instability on early ligament healing
(1991) Bray, Robert; Shrive, Nigel G.
Open Access
Experimental and analytical study of new hybrid beams constructed from high performance materials
(2010) Elmahdy, Ayman; Shrive, Nigel G.; El-Hacha, Raafat
Open Access
Finite element modelling of load transfer through articular cartilage
(1992) Van der Voet, Adrian Frank; Shrive, Nigel G.
Articular cartilage is a hydrated connective tissue lining apposing bones in synovial joints. Articular cartilage is essential for load transmission of joint forces and joint lubrication. Mechanical factors are implicated in joint diseases, such as osteoarthritis, therefore knowledge of mechanical function and properties is necessary in prevention and treatment of joint diseases. Indentation testing of intact cartilage is one method of evaluating the mechanical function and properties of articular cartilage. The first hypothesis is that indentation stiffness is affected by structural heterogeneity and mechanical anisotropy. Numerical finite element models revealed that indentation stiffness was insensitive to variations of anisotropy in the plane of the surface layer of articular cartilage. Cartilage was modelled as a poroelastic material, consisting of separate fluid and solid phases, to simulate viscoelastic mechanical behaviours due to expression of water from the matrix upon loading. A poroelastic finite element model successfully replicated mechanical behaviours of cartilage in confined compression and indentation. Also demonstrated was sensitivity of indentation stiffness to indentor roughness and permeability, cartilage layer geometry and the displacement rate of the indentor. A plane strain poroelastic finite element model of a typical whole joint tested the hypothesis that whole joints are affected by hydraulic boundary conditions which exist along the contact surface. This model simulated a displacement controlled relaxation test Results showed that hydraulically sealed boundaries at the contacting interface of apposing cartilages are a mechanically admissible condition for transmission of joint forces developed during stress relaxation. Observation of transient tensile stresses in cartilage revealed that collagen appears to function as tissue reinforcement. Vertical stress distribution in the cartilage layer was similar in shape and behaviour to that found in numerical simulations of idealized indentation tests. This suggests that indentation testing is a valid means to simulate cartilage compression behaviours in vivo. The full joint model was modified to model joint articulation. Tensile stresses, developed near the contacting interface, demonstrated that superficial collagen has a function in joint articulation. The methods used in this dissertation show promise in further investigations of mechanical behaviours of joints and mechanisms of joint disease and repair.
Open Access
Finite element modelling of masonry diaphragm walls subjected to lateral and thermal loadings
(1989) Eng, Warren; Shrive, Nigel G.
The use of masonry dates back centuries, yet only recently has research been conducted into the efficient application of this material to structures. A new form of construction which has achieved popularity in the United Kingdom is the masonry diaphragm wall. The typical diaphragm wall consists of two wythes of masonry connected at regular intervals by solid masonry webs to form box or I-sections; this form of construction is significantly stiffer than traditional forms of masonry such as the cavity wall. A properly designed diaphragm wall will fulfill many of the requirements of a b'uilding envelope and is therefore a much more efficient use of masonry. The work presented in this thesis addresses two maJor concerns with respect to the practical application of masonry diaphragm walls in Canada: the lack of adequate methods of analysis, and the performance of diaphragm walls subjected to high levels of differential thermal loading. The finite element method was the primary method of analysis utilized as extensive laboratory testing would be expensive and time-consuming. The validity of using the finite element method to model masonry diaphragm walls was verified in two phases. The first involved the modelling of a previous British test of a plain blockwork diaphragm wall. The density of the materials was found to be an important modelling parameter in free standing walls. For the second phase of the model verification, four plain masonry walls were constructed from local materials: three diaphragm walls and one cavity wall. These walls were subjected to lateral loading. The flexural tensile stresses from the finite element modelling compared favourably with the corresponding results from a simplified engineering analysis. The increased lateral load capacity of the diaphragm wall form was also confirmed. The thermal stress analysis of masonry walls subjected to large steady stat.e temperature differentials was then conducted. The finite element modelling procedure was used. The resulting principal tensile stresses in the uncompressed, plain diaphragm walls were found to be excessive, ranging from 2 to 3 MPa. The location of the maximum principal tensile stresses was in the region of the interior web-flange interface at the top of a wall. It is unlikely that masonry diaphragm walls will survive in the harsh Canadian climate without a reduction in these maxi- mum stresses. Prestressing of diaphragm walls may be required before they become viable in Canada.