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Articles 1 - 5 of 5
Full-Text Articles in Mechanical Engineering
Horses Damp The Spring In Their Step, Alan M. Wilson, M. Polly Mcguigan, Anne Su, Antonie J. Van Den Bogert
Horses Damp The Spring In Their Step, Alan M. Wilson, M. Polly Mcguigan, Anne Su, Antonie J. Van Den Bogert
Mechanical Engineering Faculty Publications
The muscular work of galloping in horses is halved by storing and returning elastic strain energy in spring-like muscle–tendon units1, 2.These make the legs act like a child's pogo stick that is tuned to stretch and recoil at 2.5 strides per second. This mechanism is optimized by unique musculoskeletal adaptations: the digital flexor muscles have extremely short fibres and significant passive properties, whereas the tendons are very long and span several joints3, 4. Length change occurs by a stretching of the spring-like digital flexor tendons rather than through energetically expensive length changes in the muscle5 …
Modal Uncoupling Of Damped Gyroscopic Systems, Jerzy T. Sawicki, G. Genta
Modal Uncoupling Of Damped Gyroscopic Systems, Jerzy T. Sawicki, G. Genta
Mechanical Engineering Faculty Publications
A new approach for uncoupling the equations of motion typical for rotordynamical systems is presented. The method does not neglect the speed-dependent e!ects, such as gyroscopic e!ects, and can be particularly valuable in the controller design of actively controlled rotors. In the presence of hysteretic type of damping, the resulting uncoupled gyroscopic systems come with an equivalent viscous damping, equivalent in a sense of yielding the same natural frequency and decay rate. The approach is illustrated through three examples of technical interest: a Je!cott rotor with hysteretic damping, a Stodola}Green rotor, and a rotor of a small gas turbine. The …
A Numerical Model For The Cyclic Instability Of Thermally Grown Oxides In Thermal Barrier Systems, Anette M. Karlsson, A. G. Evans
A Numerical Model For The Cyclic Instability Of Thermally Grown Oxides In Thermal Barrier Systems, Anette M. Karlsson, A. G. Evans
Mechanical Engineering Faculty Publications
Morphological instability of the thermally grown oxide (TGO) is a fundamental source of failure in some thermal barrier systems. The instabilities occur when initial non-planarity in the TGO grows in amplitude as the system experiences thermal cycling. By numerical means, this study explores how these instabilities are linked to constituent properties. The associated phenomena involve oxidation of the TGO, plastic flow of the bond coat, thermal expansion misfit between the TGO, bond coat and substrate, and stress relaxation in the TGO at high temperature. A key implication of the simulations is that the incidence of reverse yielding upon reheating differentiates …
In-Vivo 3d Motion Estimation Of The Shoulder Joint Utilizing Magnetic Resonance Imaging During A Simulated Push Task, D. M. Magnusson, Antonie J. Van Den Bogert, J. L. Ronsky
In-Vivo 3d Motion Estimation Of The Shoulder Joint Utilizing Magnetic Resonance Imaging During A Simulated Push Task, D. M. Magnusson, Antonie J. Van Den Bogert, J. L. Ronsky
Antonie J. van den Bogert
No abstract provided.
Modeling Nonlinear Behavior In A Piezoelectric Actuator, Hanz Richter, Eduardo A. Misawa, D. A. Lucca, H. Lu
Modeling Nonlinear Behavior In A Piezoelectric Actuator, Hanz Richter, Eduardo A. Misawa, D. A. Lucca, H. Lu
Mechanical Engineering Faculty Publications
A piezoelectric tube actuator is employed as a sample positioning device in Nanocut, a cutting instrument conceived to study the mechanics of nanometric cutting. Extension of functionality of the instrument as a nanometric machine tool motivates the search for an accurate model of the actuator for implementing feedback control. A simple nonlinear model describing longitudinal expansion of the piezoelectric tube actuator is presented in this paper. The model derivation is based on a non-formal analogy with nonlinear viscoelastic materials under uniaxial extension, for which the responses to a step input are similar to the piezoelectric tube. Suitability of the …