Optical Waveguide Theory

생체의 모델링과 Simulation

A paradigm shift has emerged over the last decade pointing to an exciting research area dealing with the harnessing of elastic structural instabilities for ‘smart’ purposes in a variety of venues. Among the different types of unstable responses, buckling is a phenomenon that has been known for centuries, and yet it is generally avoided through special design modifications. Increasing interest in the design of smart devices and mechanical systems has identified buckling and postbuckling response as a favorable behavior. The objective of this topical review is to showcase the recent advances in buckling-induced smart applications and to explain why buckling responses have certain advantages and are especially suitable for these particular applications. Interesting prototypes in terms of structural forms and material uses associated with these applications are summarized. Finally, this review identifies potential research avenues and emerging trends for using buckling and other elastic instabilities for future innovations.

https://iopscience.iop.org/article/10.1088/0964-1726/24/6/063001/pdf

Buckling-induced smart applications: recent advances and trends

Nonlinear finite element analysis of solids and structures by M.A. Crisfield

A review of topology optimization for additive manufacturing: Status and challenges

Design of compliant mechanisms using continuum topology optimization: A review

This paper presents the design methodology and fabrication process of a novel piezoresistive pressure sensor with a combined cross-beam membrane and peninsula (CBMP) diaphragm structure for micropressure measurements. The sensor is then analyzed through various experiments. The sensor is primarily designed based on the optimized sensitivity, and a finite-element method is used to predict the stresses that are induced in the piezoresistors and the deflection of the membrane under different pressures. Compared to other traditional diaphragm types, a significant increase in sensitivity can be achieved by the proposed sensor, and the membrane deflection and nonlinearity error considerably decrease. The sensor fabrication process is performed on an n-type single-crystal silicon wafer, and photolithography is used with five masks to fabricate the sensing elements. Additionally, piezoresistors are formed by boron implantation. The experimental results indicate that the fabricated sensor with the CBMP membrane yields a high sensitivity of 25.7 mV/kPa and a low nonlinearity of −0.28% full-scale span for a pressure range of 0–5 kPa at room temperature.

The Development of a New Piezoresistive Pressure Sensor for Low Pressures

This paper presents a 213-line MATLAB code for topology optimization of geometrically nonlinear structures. It is developed based on the density method. The code adopts the ANSYS parametric design language (APDL) that provides convenient access to advanced finite element analysis (FEA). An additive hyperelasticity technique is employed to circumvent numerical difficulties in solving the material density-based topology optimization of elastic structures undergoing large displacements. The sensitivity information is obtained by extracting the increment of the element strain energy. The validity of the code is demonstrated by the minimum compliance problem and the compliant inverter problem.

A 213-line topology optimization code for geometrically nonlinear structures

A method for topology optimization of hinge-free compliant mechanisms with multiple outputs using level set method is presented in this paper. The focus of this paper is on how to prevent generating the flexible hinges during the process of topology optimization of compliant mechanisms. In the proposed method, two types of mean compliances are introduced and built in the proposed multi-objective function for topology optimization of hinge-free compliant mechanisms with multiple outputs, therefore, the spring model widely used for topology optimization of compliant mechanisms is no longer needed. Some numerical examples are presented to illustrate the validity of the proposed method.

Topology optimization of hinge-free compliant mechanisms with multiple outputs using level set method

SUMMARY

A new level set method for topology optimization of distributed compliant mechanism is presented in this study. By taking two types of mean compliance into consideration, several new objective functions are developed and built in the conventional level set method to avoid generating the de facto hinges in the created mechanisms. Aimed at eliminating the costly reinitialization procedure during the evolution of the level set function, an accelerated level set evolution algorithm is developed by adding an extra energy function, which can force the level set function to close to a signed distance function during the evolution. Two widely studied numerical examples in topology optimization of compliant mechanisms are studied to demonstrate the effectiveness of the proposed method. Copyright © 2012 John Wiley & Sons, Ltd.

Benliang Zhu

Papers

Design of compliant mechanisms using continuum topology optimization: A review

The Development of a New Piezoresistive Pressure Sensor for Low Pressures

A 213-line topology optimization code for geometrically nonlinear structures

Topology optimization of hinge-free compliant mechanisms with multiple outputs using level set method

A new level set method for topology optimization of distributed compliant mechanisms