Engineering Commons^™

A Study Of A Novel Modular Variable Geometry Frame Arranged As A Robotic Surface, Christopher James Salisbury

UNLV Theses, Dissertations, Professional Papers, and Capstones

The novel concept of a "variable geometry frame" is introduced and explored through a three-dimensional robotic surface which is devised and implemented using triangular modules. The link design is optimized using surplus motor dimensions as firm constraints, and round numbers for further arbitrary constraints. Each module is connected by a passive six-bar mechanism that mimics the constraints of a spherical joint at each triangle intersection. A three dimensional inkjet printer is used to create a six-module prototype designed around surplus stepper motors powered by an old computer power supply as a proof-of-concept example.

The finite element method is applied to …

Earthquake-Induced Deformation Analysis Of A Bridge Approach Embankment In Missouri, W. Liu, Ronaldo Luna, Richard Wesley Stephenson, S. Wang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Earthquake-Induced Deformations for a Bridge Approach Earth Embankment Are Predicted using a Calibrated Numerical Model. the Constitutive Soil Model is a Modified Hyperbolic Model that Uses Masing Rules and Incremental Pore Pressure Relations. the Model Was Calibrated using Both Laboratory and Field Data. a Shaking Table Physical Model Was Used to Verify the Numerical Simulation. Additionally, the Upper San Fernando Dam Was Modeled to Reproduce the Deformations in the 1971 Earthquake. the Subsurface and Embankment Soil Conditions Were Characterized using Field and Laboratory Methods. the Model Developed Was Used to Predict the Earthquake-Induced Deformations of an Approach Embankment to Bridge …

Finite Element Analysis Of The Effect Of Low-Speed Rear End Collisions On The Medial Meniscus, Daniel J. Tichon

Master's Theses

Low-speed, rear end vehicle collisions can inflict soft tissue damage to the passenger’s knees, especially the medial meniscus, which has been previously unexplained in published literature. It is difficult to determine if factors such as age or other injury was the primary cause of the injury or if the accident acutely caused the meniscal tear. Rear end collisions may produce a combination of compressive loading and torque about the knee that will injure the medial meniscus during the initial impact and the rebound phase. The purpose of this study is to determine if it is possible for rear end low-speed …

Experimental And Numerical Development Of Anchor-Jointed Precast Structural Wall System And Optimum Design Of Prestressed Slabs, Mohamed El Semelawy

Electronic Thesis and Dissertation Repository

Precast concrete shear walls are used to resist lateral loads in low- to medium-rise buildings. An innovative joining technique is proposed to accelerate construction process and to reduce concrete damage possibility and capital loss during an earthquake event. Panels are jointed using steel anchor bolts, therefore, the system is designated "anchor-jointed precast structural wall system". In this system, anchors are utilized as a structural fuse. Damaged anchors are easily replaced after an earthquake, thus minimizing repair costs and serviceability disruptions. In the first part of this thesis, conceptual development of the system is carried out. A research program of combined …

Modeling Of Cfrp-Concrete Interface Subjected To Coupled Pull-Out And Push-Off Actions, Tayyebeh Mohammadi, Baolin Wan, Jian-Guo Dai

Civil and Environmental Engineering Faculty Research and Publications

This paper presents a finite element (FE) modeling method for predicting the IC debonding failure when the FRP/concrete interface is subjected to coupled pull-out (shear) and push-off (dowel) actions. Damaged plasticity model was used to simulate the behavior of concrete close to FRP/concrete interface. A thin damage band exposed to mixed-mode loading condition was modeled separately along the FRP-concrete interface. Cohesive elements were used to model the FRP/concrete interface. A sensitivity analysis was performed to find the appropriate damaged band dimensions, bending stiffness of FRP, and tensile strength of concrete for the model. The numerical results were validated by the …

Finite Element Reconstruction Of Real World Aortic Injury In Near-Side Lateral Automotive Crashes With Conceptual Countermeasures, Aditya Neelakanta Belwadi

Wayne State University Dissertations

Traumatic rupture of the aorta (TRA) remains the second most common cause of death associated with motor vehicle crashes after brain injury. On an average, nearly 8,000 people die annually in the United States due to blunt injury to the aorta. It is observed that more than 80% of occupants who suffer an aortic injury die at the scene due to exsanguination into the chest. With the advent of more accurate and established human body finite element (FE) models, FE crash reconstruction methods may become a valuable tool when assessing crash scenarios and occupant injury mechanisms.

The current study is …