Wildlife–aircraft collisions (wildlife strikes) with civilian and military aircraft pose notable risks and economic losses. The 4 military services within the U.S. Department of Defense maintain records regarding wildlife strikes with military aircraft. Although rotary-wing aircraft operations comprise important mission components within all 4 military services, no assessment of wildlife strike...

Modulus of rigidity (GLT) of veneer laminates was shown to be unrelated to dynamic modulus of elasticity (Eo) of single veneers and also, within the range of samples tested. unrelated to specific gravity. Values determined by the flexure test (GLR) were consistent with those from standard plate shear tests (G£T)' THE OBJECTIVE of the study reported here was to determine whether modulus of rigid...

Out-of-plane and in-plane free vibrations of angle-ply and cross-ply laminated composite beams with different boundary conditions are studied. The effect of fiber angle on out-of-plane bending, torsional, in-plane bending, and axial natural frequencies are investigated separately. The beam is modeled and analyzed by the finite element method (FEM). The finite element software package ANSYS is u...

In this study, flapwise bending vibration analysis of a tapered Timoshenko beam mounted on the periphery of a rotating rigid hub is performed. The governing differential equations of motion for pure bending are derived using the Hamilton’s principle and solved using the Differential Transform Method, DTM. During the derivation of the equations, effects of rotary inertia, shear deformation and h...

We consider a shape optimization problem in rotordynamics where the mass of a rotor is minimized subject to constraints on the natural frequencies. Our analyis is based on a class of rotors described by a Rayleigh beam model including effects of rotary inertia and gyroscopic moments. The solution of the equation of motion leads to a generalized eigenvalue problem. The governing operators are no...

A precision actuator and shaft encoder combination for remote handling in a high radiation and corrosive environment is .described. The package allows accurate positioning of beam transport components in areas where liquid lubrication is not possible. The use of hexagonal lattice metals prevents galling or seizing of the rolling surfaces. The actuator translates rotary motion and torque supplie...

Beam deflection methods such as rotary mirrors and motorized turning optical heads suffer from a variety of electro-mechanical related problems which affect laser scanning performance. These include wobble, jitter, wear, windage and synchronization issues. A novel optical structure consisting of two concentric and cylindrical interfaces with unique optical coating properties for the static proj...

The role of cold work reduction and its effect on fatigue properties are examined by means of rotary beam fatigue testing. In this study, processing parameters from the initial ingot to the final size before finish drawing were held constant. Fatigue specimens were prepared with between 20 and 55% cold work in five percent increments. These samples were subsequently heat treated, cut into test ...

Clinicians are frequently facing the dilemma of weather to perform endodontic treatment in order to retain a necrotic tooth or to extract and replace it with a dental implant. According to recent reviews, the long-term survival rates of sound or even compromised teeth surpassed those of oral implants [1, 2]. During the last decade, the endodontic therapy improved continuously due to modern equi...

This paper investigates the development of a novel framework and its implementation for the nonlinear tuning of nano/microresonators. Using geometrically exact mechanical formulations, a nonlinear model is obtained that governs the transverse and longitudinal dynamics of multilayer microbeams, and also takes into account rotary inertia effects. The partial differential equations of motion are d...