Deflection (engineering)

About: Deflection (engineering) is a research topic. Over the lifetime, 30862 publications have been published within this topic receiving 298849 citations.

Comparison of the Spherical Deflector and the Cylindrical Mirror Analyzers

Abstract: The calculated performance of electrostatic analyzers of the cylindrical and spherical deflection type are compared. It is shown that considering geometrical terms through the third order the cylindrical device is significantly superior.

The direct boundary element method in plate bending

Abstract: The direct boundary element method based on the Rayleigh-Green identity is employed for the static analysis of Kirchhoff plates. The starting point is a slightly modified version of Stern's equations. The focus is on the implementation of the method for linear elements and a Hermitian interpolation for the deflection w. The concept of element matrices is developed and the Cauchy principal values of the singular integrals are given in detail. The treatment of domain integrals, the handling of internal supports, the properties of the solution and the effect of singularities are discused. Numerical examples illustrate the various techniques. In the appendix the influence functions for the second and third derivatives of the deflection w are given.

Curvature and Tangential Deflection of Discrete Arcs: A Theory Based on the Commutator of Scatter Matrix Pairs and Its Application to Vertex Detection in Planar Shape Data

Abstract: This paper introduces a new theory for the tangential deflection and curvature of plane discrete curves. Our theory applies to discrete data in either rectangular boundary coordinate or chain coded formats: its rationale is drawn from the statistical and geometric properties associated with the eigenvalue-eigenvector structure of sample covariance matrices. Specifically, we prove that the nonzero entry of the commutator of a piar of scatter matrices constructed from discrete arcs is related to the angle between their eigenspaces. And further, we show that this entry is-in certain limiting cases-also proportional to the analytical curvature of the plane curve from which the discrete data are drawn. These results lend a sound theoretical basis to the notions of discrete curvature and tangential deflection; and moreover, they provide a means for computationally efficient implementation of algorithms which use these ideas in various image processing contexts. As a concrete example, we develop the commutator vertex detection (CVD) algorithm, which identifies the location of vertices in shape data based on excessive cummulative tangential deflection; and we compare its performance to several well established corner detectors that utilize the alternative strategy of finding (approximate) curvature extrema.

Design and modeling of a MEMS bidirectional vertical thermal actuator

Abstract: In this paper, a new micro electro-thermal actuator with bidirectional vertical motion is introduced, analyzed and tested. In traditional vertical electro-thermal actuators, the arms of actuators are fabricated with different widths to provide high and low electrical resistance for the hot and cold arms. Applying electrical current to the arms results in different thermal expansions between the hot and cold arms, which force the tip of the device to bend. The new bidirectional vertical thermal actuator (BVTA) eliminates the parasitic electrical resistance of the cold arm through the use of a 'U' shape structure. This U-shape structure provides a larger deflection with improved electrical efficiency due to the use of an active return current pass. The U-shape actuator is more beneficial in applications such as variable capacitors where a larger deflection is needed to increase the tuning range. For analysis and design purposes, an effective method to transfer the continuous system to a lumped model is presented. Simulation and test results are provided to show the deflection and effects of the design parameters on the actuator performance.