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Full-Text Articles in Mechanical Engineering

Dynamic Response Of A Hingeless Helicopter Rotor Blade At Hovering And Forward Flights, Pratik Sarker Dec 2018

Dynamic Response Of A Hingeless Helicopter Rotor Blade At Hovering And Forward Flights, Pratik Sarker

University of New Orleans Theses and Dissertations

The helicopter possesses the unrivaled capacity for vertical takeoff and landing which has made the helicopter suitable for numerous tasks such as carrying passengers and equipment, providing air medical services, firefighting, and other military and civil tasks. The nature of the aerodynamic environment surrounding the helicopter gives rise to a significant amount of vibration to its whole body. Among different sources of vibrations, the main rotor blade is the major contributor. The dynamic characteristics of the hingeless rotor consisting of elastic blades are of particular interest because of the strongly coupled equations of motion. The elastic rotor blades are subjected …


Finite Element Modeling And Experimental Characterization Of Knot Configuration Effect On The Mechanical Performance Of Surgical Suture, Arz Y. Qwam Alden Dec 2018

Finite Element Modeling And Experimental Characterization Of Knot Configuration Effect On The Mechanical Performance Of Surgical Suture, Arz Y. Qwam Alden

Dissertations

Tendon injuries in orthopedic surgery and sports medicine are escalating; hence there is great interest in improving tendon repair. The integrity of tendon repair depends in part on a combination of suture material, suture size and knot configuration. Recent studies have indicated the failure of surgical knots as a failure mode during surgical repair. Further, there is still no consensus on the ideal (best/safest) surgical knot techniques. Also, this failure mode is related to stress concentrations, which cannot be easily established with traditional tensile testing. Most researchers have focused on the measurement and comparison of the gross structural response of …


Translating Data From The Laboratory Into Simulation: A Computational Framework For Subject-Specific Finite Element Musculoskeletal Simulation, Donald R. Hume Aug 2018

Translating Data From The Laboratory Into Simulation: A Computational Framework For Subject-Specific Finite Element Musculoskeletal Simulation, Donald R. Hume

Electronic Theses and Dissertations

Computational modeling is a powerful tool which has been used to inform decisions made by engineers, scientists, and clinicians for decades. Musculoskeletal modeling has emerged as a computational modeling technique used to understand the interaction between the body and its surroundings. There are several common approaches used for musculoskeletal modeling which take advantage of different model formulations to obtain information of interest. Unfortunately, models with different joint formulations inherit disparities in representations of ligament, muscle, and cartilage at joints of interest. These differences affect the way the joint functions and limit the insight it provides through computational analysis. Musculoskeletal models …


The Effect Of Heat Generation In The Railroad Bearing Thermoplastic Elastomer Suspension Element On The Thermal Behavior Of Railroad Bearing Assembly, Oscar Osvaldo Rodriguez May 2018

The Effect Of Heat Generation In The Railroad Bearing Thermoplastic Elastomer Suspension Element On The Thermal Behavior Of Railroad Bearing Assembly, Oscar Osvaldo Rodriguez

Theses and Dissertations

Understanding the internal heat generation of the railroad bearing elastomer suspension element during operation is essential to predict its dynamic response and structural integrity, as well as to predict the thermal behavior of the complete railroad bearing assembly including the bearing adapter. The latter is essential for sensor selection and placement within the adapter (e.g., typical temperature sensors have operating ranges of up to 125°C or 257°F). The internal heat generation is a function of the loss modulus, strain, and frequency. Based on experimental studies, estimations of internally generated heat within the thermoplastic elastomer pad were obtained. The calculations show …


Modeling And Characterization Of Thermo-Oxidative Behavior Of Bismaleimide Composites, Rafid Muhammad Hussein Jan 2018

Modeling And Characterization Of Thermo-Oxidative Behavior Of Bismaleimide Composites, Rafid Muhammad Hussein

Doctoral Dissertations

"High-temperature polymer matrix composites (HTPMCs) are susceptible to thermo-oxidation, which accelerates the composites' degradation and reduces the service life. Mechanical properties of HTPMCs deteriorate due to coupled thermo-oxidation and cross-linking mechanisms. Bismaleimides (BMIs) are commonly used high-temperature resins for aerospace applications. This work presents the viability of using experimental weight loss to model the spatial distribution of oxidation when the oxidized polymer matrix is not discernible. Three tasks are introduced: (1) Anisotropic oxidation prediction using optimized weight loss behavior of bismaleimide composites, (2) A multi-scale modeling of thermo-oxidative effects on the flexural behavior of cross-ply bismaleimide composites, and (3) Thermo-oxidative …