H. T. Wang, L. Shi

The International Conference on Computational & Experimental Engineering and Sciences, Vol.19, No.1, pp. 11-12, 2011, DOI:10.3970/icces.2011.019.011

Abstract A three-dimensional fast boundary element solver is developed for the shape optimization of nozzles of nuclear reactor pressure vessels (RPVs). In a RPV, pressure and mechanical loads may lead to high stress concentration due to the discontinuity of the structure, especially at the inner surface of the cold/hot legs. This work aims to minimize these stress concentrations by optimizing the geometry of the openings using modern shape optimization techniques and fast boundary element method. Shape optimization methods based on the principle of biological adaptive growth are incorporated into a boundary element method program and used More >

Song Zhang, Yajun Wang, Laura Ekstrand, Ying Xu, Yuanzheng Gong

The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.2, pp. 39-40, 2011, DOI:10.3970/icces.2011.018.039

Abstract High-speed, high-resolution 3-D shape measurement has become increasingly important, with broad applications including medicine, homeland security, and entertainment. Techniques such as structured light, stereovision, and LIDAR have led the way in this field. In recent years, we have made some progress, developing an unprecedented 60 Hz system utilizing a digital fringe projection and phase-shifting method and simultaneously achieving 40 Hz 3-D shape acquisition, reconstruction, and display. However, a conventional digital fringe projection system requires the computer to generate sinusoidal fringe patterns to be sent to the projector. Because 8 bits are usually needed to represent… More >

Zonghua Zhang

The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.2, pp. 33-34, 2011, DOI:10.3970/icces.2011.018.033

Abstract Optical full-field fringe projection techniques have been widely studied in academia and applied to many actual industrial fields of automatic inspection, reverse engineering, heritage protection, cosmetic surgery, and so on. With the advent of color CCD cameras and Digital Micromirror Device (DMD) based color Digital Light Processing (DLP) projectors, their major red, green and blue channels have been used as a carrier to code fringe patterns. Since three fringe patterns can be simultaneously projected and captured by a color image, the acquisition time reduces to 1/3 of the value by projecting only gray fringe patterns.… More >

L.Y. Wang, W. B. Song Z.D. Wang

The International Conference on Computational & Experimental Engineering and Sciences, Vol.17, No.1, pp. 13-14, 2011, DOI:10.3970/icces.2011.017.013

Abstract Shape memory epoxies and their composites have great potential applications in future deployable space structures industry. In this study six types of shape memory epoxies with different shape transition temperatures were synthesized by varying the curing agents and their contents. Thermal frozen/recovery test, DSC and DMA were performed to investigate their shape memory behaviors and thermomechanical properties. Further discussions about the testing results were presented with consideration of the microstructure. More >

Zhengfa Li, Weibin Song, Zhengdao Wang

The International Conference on Computational & Experimental Engineering and Sciences, Vol.17, No.1, pp. 11-12, 2011, DOI:10.3970/icces.2011.017.011

Abstract By using the high froze/recovery strains of shape memory polymers to meet the requirements of deployable space structures, the folding behavior of shape memory tape spring structures consisting of shape memory polymer and metal spring was analyzed. Firstly, numerical simulations were performed on the buckling modes and affecting factors under the equal- and opposite-sense bends. The results show that the folding deformations of such structure in the two cases are completely different. The equal-sense bending leads to the structure buckled abruptly, but gradual torsion buckling is received in the case of opposite-sense bending. The critical More >

Zhenhan Yao, Yintao Wei

The International Conference on Computational & Experimental Engineering and Sciences, Vol.16, No.2, pp. 51-52, 2011, DOI:10.3970/icces.2011.016.051

Abstract Shape optimization is very important in many engineering fields. As conventional engineering design, the shape optimization is generally based on the finite element analysis. Because many engineering strutures are related to different nonlinear problems in their working state, the analysis for each design sample is quite time consuming. For example for the shape optimization of automotive tires, it is related to the geometrical, material nonlinearity, and boundary nonlinearity caused by the contact problem. Therefore, the finite element analysis combined with sensitivity analysis to get more information for each design sample is a strategy usually adopted.… More >

Syh-Tsang Jenq, Yuen-Sheng Chiu

The International Conference on Computational & Experimental Engineering and Sciences, Vol.16, No.1, pp. 15-16, 2011, DOI:10.3970/icces.2011.016.015

Abstract Current work studies the transient hydroplaning behaviors of 200 kPa inflated pneumatic radial tires with V-shaped grooved tread patterns and then rolls over the water film with a thickness of 10 mm. we also perform complete numerical simulations in order to know how to elevate the hydroplaning capability. Tires were numerically loaded with a quarter car weight of 4 kN on initial step, and then subsequently accelerated from rest rolling over a water film with a thickness of 10 mm on top of a flat roadway. Tire structure is composed of outer rubber tread and… More >

Hana Chang^*, Melissa L. Knothe Tate^∗,†,‡

Molecular & Cellular Biomechanics, Vol.8, No.4, pp. 297-318, 2011, DOI:10.3970/mcb.2011.008.297

Abstract In the preceding study (Part A), we showed that prescribed seeding conditions as well as seeding density can be used to subject multipotent stem cells (MSCs) to volume changing stresses and that changes in volume of the cell are associated with changes in shape, but not volume, of the cell nucleus. In the current study, we aim to control the mechanical milieu of live cells using these prescribed seeding conditions concomitant to delivery of shape changing stresses via fluid flow, while observing adaptation of the cytoskeleton, a major cellular transducer that modulates cell shape, stiffness… More >

Joshua A. Zimmermann^*, Melissa L. Knothe Tate^∗,†,‡

Molecular & Cellular Biomechanics, Vol.8, No.4, pp. 275-296, 2011, DOI:10.3970/mcb.2011.008.275

Abstract Shape and fate are intrinsic manifestations of form and function at the cell scale. Here we hypothesize that seeding density and protocol affect the form and function of live embryonic murine mesenchymal stem cells (MSCs) and their nuclei. First, the imperative for study of live cells was demonstrated in studies showing changes in cell nucleus shape that were attributable to fixation per se. Hence, we compared live cell and nuclear volume and shape between groups of a model MSC line (C3H10T1/2) seeded at, or proliferated from 5,000 cells/cm2 to one of three target densities to… More >

C.J. Zheng¹, H.B. Chen¹, T. Matsumoto², T. Takahashi²

CMES-Computer Modeling in Engineering & Sciences, Vol.79, No.1, pp. 1-30, 2011, DOI:10.3970/cmes.2011.079.001

Abstract A fast multipole boundary element approach to the shape sensitivity analysis of three dimensional acoustic wave problems is developed in this study based on the adjoint variable method. The concept of material derivative is employed in the derivation. The Burton-Miller formula which is a linear combination of the conventional and normal derivative boundary integral equations is adopted to cope with the non-uniqueness problem when solving exterior acoustic wave problems. Constant elements are used to discretize the boundary surface so that the strongly- and hyper-singular boundary integrals contained in the formulations can be evaluated explicitly and More >