Dynamics of structures

Nonlinear Oscillations: Exact Solutions and their Approximations

Recent developments of meshfree and particle methods and their applications in applied mechanics are surveyed. Three major methodologies have been reviewed. First, smoothed particle hydrodynamics ~SPH! is discussed as a representative of a non-local kernel, strong form collocation approach. Second, mesh-free Galerkin methods, which have been an active research area in recent years, are reviewed. Third, some applications of molecular dynamics ~MD! in applied mechanics are discussed. The emphases of this survey are placed on simulations of finite deformations, fracture, strain localization of solids; incompressible as well as compressible flows; and applications of multiscale methods and nano-scale mechanics. This review article includes 397 references. @DOI: 10.1115/1.1431547#

Meshfree and particle methods and their applications

Chatter is a self-excited vibration that can occur during machining operations and become a common limitation to productivity and part quality. For this reason, it has been a topic of industrial and academic interest in the manufacturing sector for many years. A great deal of research has been carried out since the late 1950s to solve the chatter problem. Researchers have studied how to detect, identify, avoid, prevent, reduce, control, or suppress chatter. This paper reviews the state of research on the chatter problem and classifies the existing methods developed to ensure stable cutting into those that use the lobbing effect, out-of-process or in-process, and those that, passively or actively, modify the system behaviour.

Chatter in machining processes: A review

https://www.heikohoffmann.de/documents/hoffmann_kpca_preprint.pdf

Kernel PCA for novelty detection

Vibration based Structural Health Monitoring using output-only measurements under changing environment

For high wave numbers, the Helmholtz equation suffers the so-called 'pollution effect'. This effect is directly related to the dispersion. A method to measure the dispersion on any numerical method related to the classical Galerkin FEM is presented. This method does not require to compute the numerical solution of the problem and is extremely fast. Numerical results on the classical Galerkin FEM (p-method) is compared to modified methods presented in the literature. A study of the influence of the topology triangles is also carried out. The efficiency of the different methods is compared. The numerical results in two of the mesh and for square elements show that the high order elements control the dispersion well. The most effective modified method is the QSFEM [1, 2] but it is also very complicated in the general setting. The residual-free bubble [3, 4] is effective in one dimension but not in higher dimensions. The least-square method [1, 5] approach lowers the dispersion but relatively little. The results for triangular meshes show that the best topology is the 'criss-cross' pattern. Copyright © 1999 John Wiley & Sons, Ltd.

Dispersion and pollution of the FEM solution for the Helmholtz equation in one, two and three dimensions

A six-axis single-stage active vibration isolator based on Stewart platform

Zero gravity experiment of a six-axis single stage active vibration isolator based on stewart platform

This article focuses on the modeling of structures equipped with Macro Fiber Composite (MFC) transducers. Based on the uniform field method under the plane stress assumption, we derive analytical mixing rules in order to evaluate equivalent properties for d31 and d33 MFC transducers. In particular, mixing rules are derived for the longitudinal and transverse piezoelectric coefficients of MFCs. These mixing rules are validated using finite element computations and experimental results available from the literature.

/pdf/mixing-rules-for-the-piezoelectric-properties-of-macro-fiber-lzv7aqzm83.pdf

Arnaud Deraemaeker

Papers

Vibration based Structural Health Monitoring using output-only measurements under changing environment

Dispersion and pollution of the FEM solution for the Helmholtz equation in one, two and three dimensions

A six-axis single-stage active vibration isolator based on Stewart platform

Zero gravity experiment of a six-axis single stage active vibration isolator based on stewart platform

Mixing Rules for the Piezoelectric Properties of Macro Fiber Composites