Abstract: Publication date: September 2019Source: Advances in Engineering Software, Volume 135Author(s): Robert Klinc, Žiga Šebenik, Matjaž Dolšek, Marko Brozovič, Matevž Dolenc In the paper a web-based system CGMapp for the selection of characteristic ground motions is presented. It performs the selection of ground motions according to the conditional spectrum approach by considering the old PEER and RESORCE databases, and refines this selection by making use of nonlinear dynamic analyses of a single-degree-of-freedom (SDOF) model, so that seven characteristic ground motions are obtained. They can be understood as risk-targeted, hazard-consistent, and structure-specific ground motions, which can be used within the scope of the 3R method (Record selection, Response analysis and Risk-based decision making) in order to make decisions about the collapse safety of symmetric buildings, by performing only a few nonlinear response history analyses. It was shown by the proposed web-based system that the automation of the selection of the characteristic ground motions is possible through the internet. Thus, the use of the 3R method becomes trivial, so that the researcher will have the possibility to test the method, which will help to better understand the range of applicability of the proposed 3R method. In the paper, the background of CGMapp is first explained. This is followed by a demonstration of the use of the presented web-based system for the selection of characteristic ground motions in the assessment of the collapse safety of an 8-storey reinforced concrete dual structure. Although only seven nonlinear dynamic analyses were performed using characteristic ground motions, it is shown that the decision about collapse safety was the same as that obtained on the basis of incremental dynamic analysis, which requires hundreds of simulations. Finally, it is also shown that the web-based system can be used as a research tool, in order to obtain a better understanding of the impact of the uncertainty of the selection of ground motions on decision-making in earthquake engineering.

Abstract: Publication date: September 2019Source: Advances in Engineering Software, Volume 135Author(s): M.A. Latif, M.P. Saka In this study, optimum design algorithm is presented for tied-arch bridges under AASHTO-LRFD Bridge Design Specifications provisions. It is decided that in tied-arch bridges ties, arch ribs, and bottom and top bracings are made of built-up box sections, whereas built-up I sections are utilized for floor beams and stringers. Bars are adopted for hangers. In the formulation of the optimization problem, design variables are selected as the cross sectional dimensions of steel plates not that of I and box sections. Design pools are prepared for steel plate sections in addition to the hanger bars so that the optimization algorithm can select appropriate steel plates, construct I and box built-up sections for members of 3-D tied-arch such that the weight of the bridge is minimized. In addition to design code requirements, geometrical constraints among its elements that are required for manufacturability of the bridge are also considered. The design process of tied-arch bridges differs from that of steel framed structures. It necessitates consideration of moving vehicle loads. Design optimization algorithms require the response of bridges under several design load arrangements and in the construction of influence lines. This is achieved by using open application programming interface (OAPI) facility of SAP2000. The solution of discrete nonlinear programming problem is obtained by using the proposed Enhanced Artificial Bee Colony algorithm (eABC). The proposed algorithm is compared with Standard Artificial Bee Colony (ABC) and Exponential Big Bang-Big Crunch (eBB-BC) algorithms to evaluate its performance.

Abstract: Publication date: September 2019Source: Advances in Engineering Software, Volume 135Author(s): Libin Zhang, Jiacai Wang, Jiaoliao Chen, Kang Chen, Bangyang Lin, Fang Xu The robot dynamics model can improve the efficiency of robot manipulators to perform complex tasks. In this study, a novel method is proposed for the dynamics model of a 6 degree of freedom (DOF) robot manipulator to improve the motion accuracy. A centrosymmetric static friction model (CSFM) integrated with a piecewise function is utilized to describe the hysteresis effect of joint friction. A hybrid whale optimization algorithm and genetic algorithm (WOA-GA) is applied to identify dynamic parameters of the 6 robot joints. An experiment conducted on a 6-DOF robot manipulator demonstrates that the mean deviation of the estimated torque of robot joints for slow motion is reduced by 19% using CSFM in contrast to the Stribeck model. The mean match degree of the estimated torque can reach to 93.86% based on WOA-GA, improved by 0.4–2% compared with other optimization algorithms (WOA, GA and PSO-GA). These results prove that the method based on CSFM and WOA-GA is feasible for the precise dynamics model of a robot manipulator.

Abstract: Publication date: September 2019Source: Advances in Engineering Software, Volume 135Author(s): Shandong Peng, Han Ding, Jinyuan Tang In order to meet the high strength demand from gear transmission in industrial applications, identification of loaded tooth contact performance using loaded tooth contact analysis (LTCA) has become an increasing important design stage for spiral bevel gears. To distinguish with the conventional simulated loaded tooth contact analysis (SLTCA) applying commercial finite element software, a numerical loaded tooth contact analysis (NLTCA) method is proposed to determine the loaded contact pressure and stress. In particular, focusing on the time-varying meshing characteristics of loaded tooth contact, the loaded contact pressure and stress distributions on both instantaneous and whole contact ellipses of tooth surface are determined by the proposed NLTCA, respectively. First, the universal mathematical tooth surface mode is established by applying machine settings satisfying the universal motion concept (UMC). Moreover, the curvature analysis of the contact points is performed to determine the loaded tooth surface contact pattern as the input for the proposed numerical analytical calculation method. In the identifications of loaded contact pressure and stress, their distributions having the different directions in both the instantaneous contact ellipse and the whole loaded contact pattern are taken into account. Finally, the numerical instances are given to verify the proposed methodology.

Abstract: Publication date: August 2019Source: Advances in Engineering Software, Volume 134Author(s): Te Chen, Long Chen, Xing Xu, Yingfeng Cai, Haobin Jiang, Xiaoqiang Sun This paper investigates the fault-tolerant path following control problem of autonomous ground electric vehicles with in-wheel motors through hierarchical control strategy. The sliding mode observer with boundary layer is designed to estimate the vehicle state, and the time-delay estimation method is used to compute the actuator fault. Considering the actuator fault, the fault-tolerant path following control strategy is proposed, in which the upper layer controller is developed to achieve path following control and guarantee vehicle stability simultaneously by sliding mode control method, and the lower layer controller is presented to achieve the control efforts of upper layer controller by adaptive orientated tire force allocation method. The simulations are implemented in the CarSim-Simulink co-simulation platform, and the simulation results have verified the effectiveness of proposed fault-tolerant path following control method.

Abstract: Publication date: August 2019Source: Advances in Engineering Software, Volume 134Author(s): Erfan Niazi, James G. McDonald, Marianne Fenech Over the past several decades, image processing and automated tracking of particles has emerged as a useful tool for the study of biological particles behaviour. This article describes an open-source computational implementation of a method for determining particle velocity and size distributions of large groups of particles by analyzing video sequences acquired using a video-microscopic systems. Although, in this study, red blood cells are used as a subject, this implementation can be used for any particle-laden flow where particles present a range of sizes and details of the velocity distribution of each size is of interest.From each single image, the current program detects particles and classifies them according to their size. It uses sequential images to track particles and compute the instantaneous velocity distribution of the particles. The tool can also assign an ellipse to each particle and report the major axis, the minor axis and the orientation of particles in each image. Use of the program improves repeatability of image processing and is suitable for studies related to particle dynamics, colloids, and microfluidic flow measurement. The size distribution and the velocity distribution of particles is often useful in the study of effect of parameters like shear stress on particle collision rate, agglomeration and breakage rate.

Abstract: Publication date: August 2019Source: Advances in Engineering Software, Volume 134Author(s): Chunming Fu, Lixiong Cao An interval differential evolution (IDE) with adaptive subinterval decomposition analysis is suggested to directly solve the nonlinear uncertain optimization problems with interval parameters. The adaptive subinterval decomposition analysis technique is proposed to calculate the upper and lower bounds of objective function and constraints caused by interval uncertainties. An adaptive convergence mechanism is utilized to ensure the accuracy of achieved bounds. Moreover, within the framework of IDE, the interval possibility model is employed to deal with the interval constraints of uncertain optimization problems and the interval preferential rule is used to select the promising solutions to retain into the next evolutionary population. Both numerical and engineering examples are eventually given to demonstrate the validity of the proposed method.

Abstract: Publication date: Available online 19 January 2007Source: Advances in Engineering SoftwareAuthor(s): T.T. Tanyimboh, A.B. TemplemanThis article has been removed consistent with Elsevier Policy on Article Withdrawal. The Publisher apologises for any inconvenience this may cause.