OBJECTIVE The purpose of this study was to determine the fracture strength of zirconium implant abutments and the torque required to unfasten the retaining screw before and after applying cyclic loading to the implant-abutment assembly. The dynamic behavior and stress distribution pattern of zirconium abutments were also evaluated. METHODS AND MATERIALS Static and cyclic loading of 7 XiVE imp...

Ultra High Molecular Weight Polyethylene (UHMWPE) is a polymeric material employed in critical biomedical applications. Knowledge of its mechanical behavior is essential in order to obtain accurate prediction of stresses and deformations in real components, in particular when cyclic loading is considered. In the present research the effects of alternating and pulsating cyclic strain on the mech...

Epidemiologic studies indicate that repetitive (cyclic) occupational activities lead to a cumulative trauma disorder (CTD), and the frequency or velocity of the movement is one of the risk factors. Experimental neurophysiological evidence to confirm the epidemiology is not available. The response of the multifidus muscles to cyclic loading in anterior lumbar flexion-extension was assessed to te...

Six formulas representing what is commonly referred to as “daily load stimulus” are identified, compared and tested in their ability to relate skeletal mechanical loading to bone maintenance and osteogenic response. Particular emphasis is placed on exerciseinduced skeletal loading and whether or not the formulas can adequately capture the known experimental observations of saturation of continu...

Tendinopathy affects individuals who perform repetitive joint motion. Magnetic resonance imaging (MRI) is frequently used to qualitatively assess tendon health, but quantitative evaluation of inherent MRI properties of loaded tendon has been limited. This study evaluated the effect of cyclic loading on T₂* values of fresh and frozen rabbit patellar tendons using ultra short echo (UTE) MRI. Eigh...

Although fatigue damage in bone induced by cyclic loading has been recognized as a problem of clinical significance, few fracture mechanics based studies have investigated how incipient cracks grow by fatigue in this material. In the present study, in vitro cyclic fatigue experiments were performed in order to quantify fatigue-crack growth behavior in human cortical bone. Crack-growth rates spa...

Title of Document: A NON-LINEAR DAMAGE MODEL WITH LOAD DEPENDENT EXPONENTS FOR SOLDERS UNDER SEQUENTIAL CYCLIC SHEAR LOADS Elviz George, Ph.D., 2015 Directed By: Professor Michael G. Pecht, Department of Mechanical Engineering The damage state of a material subject to cyclic loads is often characterized by the cycle ratio of applied cycles to the number of survivable cycles. The damage in a mat...

several relationships to assess at-rest pressure coefficient in retaining walls, have been developed by different researchers. these suggested relationships are generally a function of mechanical soil parameters such as internal friction angel, poison ratio and over-consolidation ratio. in integral bridges, however, this coefficient is also a function of many other parameters other than soil ch...

An assessment of the material properties of three types of touch and close fasteners (Velcro) in general orthopaedic usage is presented. The materials were tested under various loading regimes using an Instron testing machine. The force-extension curves were analyzed and values determined for both the stiffness and strength of the various attachments. Particular reference was made to the altera...

A load deflection and a cyclic loading apparatus capable of measuring dorsiflexion/plantarflexion, pronation/supination, internal/external rotation, and cyclic dorsiflexion (60 cycles per minute) of ankle-foot prostheses are described. A test protocol was developed to assess the functional parameters of the Jaipur ankle-foot prosthesis before and after prolonged cyclic loading, with the simulta...