No description available.

Many soft food materials, including vegetable shortening, exhibit complex rheological behaviour with properties that resemble those of a solid and a liquid simultaneously. The fundamental parameters used to describe the rheological response of vegetable shortening were obtained from uniaxial compression tests, including monotonic and cyclic compression, as well as creep and stress relaxation tests. The fundamental parameters obtained from the various compression tests were then used in two mechanical models (viscoelastic and elasto-visco-plastic) to predict the compression and conical indentation response of vegetable shortening. The accuracy of the two models was studied with the help of the commercially available finite element analysis software package Abaqus. It was determined that the viscoelastic model was not suitable for the prediction of the rheological response of shortening. On the other hand, the proposed elasto-visco-plastic model predicted with reasonable accuracy the uniaxial compression and indentation experimental response of vegetable shortening.

Many soft food materials, including vegetable shortening, exhibit complex rheological behaviour with properties that resemble those of a solid and a liquid simultaneously. The fundamental parameters used to describe the rheological response of vegetable shortening were obtained from uniaxial compression tests, including monotonic and cyclic compression, as well as creep and stress relaxation tests. The fundamental parameters obtained from the various compression tests were then used in two mechanical models (viscoelastic and elasto-visco-plastic) to predict the compression and conical indentation response of vegetable shortening. The accuracy of the two models was studied with the help of the commercially available finite element analysis software package Abaqus. It was determined that the viscoelastic model was not suitable for the prediction of the rheological response of shortening. On the other hand, the proposed elasto-visco-plastic model predicted with reasonable accuracy the uniaxial compression and indentation experimental response of vegetable shortening.

The jaw musculature of Champsosaurus has been enigmatic since the taxon was first described. The extant phylogenetic bracketing method is used to determine the morphology of the jaw adductor musculature. Rotational mathematics is used to calculate the muscle forces, torques, angular accelerations, and angular velocities generated by the jaw muscles. The mechanical strength of the skulls of neochoristoderes and crocodilians are investigated using finite element analysis. Finally, the hydrodynamic performance of the skulls of neochoristoderes and crocodilians is studied. The analysis is used to compare neochoristoderes to their extant ecological analogues, crocodilians, and determine the palaeoecological implications of the results. It was found that Champsosaurus rotates the lower jaw faster, the mechanical strength was lower, and shows better hydrodynamic performance than crocodilians. The results suggest that Champsosaurus was ideally suited to prey upon small or juvenile fish, and did not overlap its niche with sympatric crocodilians. / Systematics and Evolution

Scoliosis is defined as the abnormal three dimensional curvature of the spine with 80% of all cases being idiopathic in nature. If left unchecked, this condition can cause cardio-pulmonary complications and occasionally death. Currently, the most common method of treatment of scoliosis is through mechanical bracing or in extreme cases, corrective surgery. Current treatments can be further improved with a greater understand of the growth patterns of scoliotic spines. The objective of this study is to develop a finite element spine model capable of responding to loading conditions in a similar fashion to previous finite biomechanics spine model and utilize the ‘vicious cycle’ scoliosis theory in an effort to model scoliosis growth. Using CT images of a healthy spine, a three dimensional finite element model of the L3-L4 vertebra is generated. Asymmetric loading due to compression and muscle forces can then be applied on the spine and the resultant stresses are then translated into equivalent thermal load. Using this thermal load, it is possible to cause the spine model to grow, thereby predicting the growth pattern of a spine due to asymmetric loading.

The thesis presents a Finite Element Analysis (FEA) based wear modelling algorithm devised in the course of the reported research activity. FEA is used as a tool to calculate nodal pressures at the contact region for small sliding steps. These pressures are then inputted to a customised wear calculating routine. The routine uses averaged wear coefficients (wear rates) obtained from custom designed experiments. The FEA contact geometry is modified after each sliding step to account for the contact height decay, thus determining the volume loss due to wear over usage time, thus predicting the worn geometry. Consequently, the designer gains invaluable insight into the extent of wear-caused component deformation along with the number of usage cycles lapsed prior to such deformation.

Gussets plates are used in truss structures to connect multiple members. It is for this reason that it is important that the gusset plate have adequate strength to transfer forces between members, otherwise a failure in a gusset plate can cause the entire truss structure to fail. This study will focus on a gusset plate that is believed to have been under designed on the I-35W Minneapolis bridge. Three possible sources of failure will be investigated: yielding of the gusset plate, fracture of the gusset plate, and buckling of the gusset plate. Various sources such as the plans for the truss and an interim report on its failure will be utilized to construct the model for the finite element analysis. The results obtained from the finite element analysis and the traditional analysis approach using uniform force method will be used to investigate the failure of the gusset plate.

Despite many research pieces on brake systems, there is still research to be done on brake pad geometry and the dissipation of heat during brake engagements using the finite element analysis method. Brake application is a process in which the kinetic energy of the vehicle is mostly converted into thermal energy and then dissipated in the form of heat. Based on dynamometer test results it was seen that brake pad temperatures could reach up to 600° C [23]. Preliminary research using computer modeling software has shown that heat dissipation in brake pads with wavy geometries and air channels from the top to bottom is much better compared to pads that do not have those specific features. Brake pads that dissipate heat faster are prone to brake fade and other braking issues that may arise due to overheating [15]. For this research, two readily available brake pads and two designs of brake pads with new geometry were modeled using CAE software. Finite element analysis was then performed to test how well each brake pad dissipated heat after reaching brake fade temperatures. The readily available brake pads were from Power Stop and Wagner [26]. ANSYS Space Claim [25] was used to design and model the brake pads, ANSYS 18.2 [24] was used to perform the finite element analysis on the pads. After performing the analysis, results indicate that a brake pad with a design that had zones for turbulent air at ambient conditions and convection slots from the top to the bottom decreased in temperature by about 90° C more in the same time compared to the conventional design. By studying the changing values of the convection heat transfer coefficient with velocity, the placing of the turbulence zones can be more precise in order attain greater airflow to remove heat from the brake pad quicker.

No description available.

No description available.