A micro-accelerometer MDO benchmark problem

Many optimization and coordination methods for multidisciplinary design optimization (MDO) have been proposed in the last three decades. Suitable MDO benchmark problems for testing and comparing these methods are few however. This article presents a new MDO benchmark problem based on the design optimization of an ADXL150 type lateral capacitive micro-accelerometer. The behavioral models describe structural and dynamic effects, as well as electrostatic and amplification circuit contributions. Models for important performance indicators such as sensitivity, range, noise, and footprint area are presented. Geometric and functional constraints are included in these models to enforce proper functioning of the device. The developed models are analytical, and therefore highly suitable for benchmark and educational purposes. Four different problem decompositions are suggested for four design cases, each of which can be used for testing MDO coordination algorithms. As a reference, results for an all-in-one implementation, and a number of augmented Lagrangian coordination algorithms are given. © 2009 The Author(s)

Structural Behavior Analysis and Optimization, Integrating MATLAB with Autodesk Robot

The concepts of structural behavior analysis and optimization have started to be combined in the latest decades with an increasing trend also due to the need of often meeting performance targets, high structural complexity and costs. Nonetheless, existing approaches tackled this issue mainly in the domain of static calculations or referring to a specific type of optimization (e.g., size, topology or geometry). A new methodology is proposed to systematically perform different types of analysis (e.g., linear and nonlinear), by exploiting the Autodesk Robot Structural Analysis API through MATLAB. This approach involves the adoption of ActiveX technologies for the manipulation of COM (Component Object Model) objects in the MATLAB environment. A real-world example of linear dynamic modal analysis is also presented and a synthetic diagnostic of the structure is conducted based on the displacements resulting from the calculation

A single-ion trap with minimized ion–environment interactions

We present a new single-ion endcap trap for high-precision spectroscopy that has been designed to minimize ion–environment interactions. We describe the design in detail and then characterize the working trap using a single trapped (Formula presented.) ion. Excess micromotion has been eliminated to the resolution of the detection method, and the trap exhibits an anomalous phonon heating rate of (Formula presented.). The thermal properties of the trap structure have also been measured with an effective temperature rise at the ion’s position of (Formula presented.). The small perturbations to the ion caused by this trap make it suitable to be used for an optical frequency standard with fractional uncertainties below the (Formula presented.) level.</p