A finite element simulation on a fracture fixated clavicle was performed to study the effects of different fracture fixation parameters on the callus region. Specifically, parameters such as plate material, thickness, plate/bone gap, screw length, and locking vs. non-locking screws were explored. Plate thickness and locking vs. non-locking screws were found to be influential to construct stiffness where plate/bone gap and number of screws were not as sensitive.

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A new retinal reattachment surgical procedure is based on a stent that is deployed to press the retina back in place. An eye-stent finite element model studied the strain induced by the stent on retina. Finite element model simulations were performed for several stent geometric configurations (number of loops, wire diameter, and intraocular pressure). The finite element model was validated against experiment. Parametric studies demonstrated that stents could be successfully designed so that the maximum strain would be below permanent damage strain threshold of 2%.

The development of a new class of devices for the suppression of structural vibration becomes possible by exploiting the unique properties of single-crystal piezoceramics. These vibration absorbers will be compact, robust, and demand minimal power for operation. They will be characterized by frequency agility, which means that the absorber tuning parameters can adapt rapidly to controller command and tuning can be accomplished over a wide frequency range. Identified applications include control of turbomachinery vibration, flexible space structures, jitter control in optical systems, and vibration isolation in machinery mounts. The current state-of-the-art adaptive vibration absorber tuning range is fundamentally limited by the electromechanical coupling of presently available polycrystalline piezoceramic materials. The narrow tuning range characteristic of current vibration absorbers severely limits the implementation of the solid-state absorber concept. This work presents efforts related to the design of vibration absorbers that use the single-crystal piezoceramic large electromechanical coupling to achieve greatly enhanced tuning over a wide frequency range. Absorber electromechanical coupling-coefficients greater than 50% were obtained. Design issues specifically related to the use of single crystals in vibration absorbers were identified and addressed. Several device configurations were analyzed and tested. Good agreement was observed between analytical and experimental results.

Protection from the potentially damaging effects of shock loading is a common design requirement for diverse mechanical structures ranging from shock accelerometers to spacecraft. High damping viscoelastic materials are employed in the design of geometrically complex, impact-absorbent components. Since shock transients are characterized by a broad frequency spectrum, it is imperative to properly model frequency dependence of material behavior over a wide frequency range. The Anelastic Displacement Fields (ADF) method is employed herein to model frequency-dependence within a time-domain finite element framework. Axisymmetric, ADF finite elements are developed and then used to model shock propagation and absorption through viscoelastic structures. The model predictions are verified against longitudinal wave propagation experimental data and theory.