Open Access
ARTICLE
Tienfuan Kerh1,2, J.S. Lai1, D. Gunaratnam2, R. Saunders2
CMES-Computer Modeling in Engineering & Sciences, Vol.26, No.1, pp. 1-12, 2008, DOI:10.3970/cmes.2008.026.001
Abstract Taiwan frequently suffers from strong ground motion, and the current building code is essentially based on two seismic zones, A and B. The design value of horizontal acceleration for zone A is 0.33g, and the value for zone B is 0.23g. To check the suitability of these values, a series of actual earthquake records are considered for evaluating peak ground acceleration (PGA) for each of the zones by using neural network models. The input parameters are magnitude, epicenter distance, and focal depth for each of the checking stations, and the peak ground acceleration is calculated as the output with the… More >
Open Access
ARTICLE
Jin-Ho Roh1, In Lee2
CMES-Computer Modeling in Engineering & Sciences, Vol.26, No.1, pp. 13-30, 2008, DOI:10.3970/cmes.2008.026.013
Abstract A methodology to maintain the configuration of inflated membrane structures using shape memory alloy (SMA) film actuator is numerically investigated. The two- dimensional incremental formulation of the SMA constitutive model is developed. New parameters related to the thermodynamic energy equation are introduced to describe more general behaviors of the SMA film. With numerical algorithm of wrinkling and SMAs, the interactions between the inflated membrane structure and the SMA film are investigated by using a finite element program. The effectiveness of SMA film to control the configuration of an inflated membrane structure is examined. To demonstrate surface configuration control, two inflatable… More >
Open Access
ARTICLE
Amit Shaw1, B. Banerjee1, D Roy1,2
CMES-Computer Modeling in Engineering & Sciences, Vol.26, No.1, pp. 31-60, 2008, DOI:10.3970/cmes.2008.026.031
Abstract A generalization of a NURBS based parametric mesh-free method (NPMM), recently proposed by Shaw and Roy (2008), is considered. A key feature of this parametric formulation is a geometric map that provides a local bijection between the physical domain and a rectangular parametric domain. This enables constructions of shape functions and their derivatives over the parametric domain whilst satisfying polynomial reproduction and interpolation properties over the (non-rectangular) physical domain. Hence the NPMM enables higher-dimensional B-spline based functional approximations over non-rectangular domains even as the NURBS basis functions are constructed via the usual tensor products of their one-dimensional counterparts. Nevertheless the… More >
Open Access
ARTICLE
Shu Li1, S. N. Atluri2
CMES-Computer Modeling in Engineering & Sciences, Vol.26, No.1, pp. 61-74, 2008, DOI:10.3970/cmes.2008.026.061
Abstract The Meshless Local Petrov-Galerkin (MLPG) "mixed collocation'' method is applied to the problem of topology-optimization of elastic structures. In this paper, the topic of compliance minimization of elastic structures is pursued, and nodal design variables which represent nodal volume fractions at discretized nodes are adopted. A so-called nodal sensitivity filter is employed, to prevent the phenomenon of checkerboarding in numerical solutions to the topology-optimization problems. The example results presented in the paper demonstrate the suitability and versatility of the MLPG "mixed collocation'' method, in implementing structural topology-optimization. More >