Yunping Liu^{1, 2, *}, Xingxing Yan¹, Fei Yan¹, Ze Xu¹, Weiyan Shang³

CMC-Computers, Materials & Continua, Vol.63, No.1, pp. 469-487, 2020, DOI:10.32604/cmc.2020.05746 - 30 March 2020

Abstract Due to the coupled motion between the rotor unmanned aerial vehicle (UAV) and the manipulator, the underactuation characteristics of the system itself, and the influence of external uncertainties, the stability of the rotor UAV’s manipulator control system is difficult to control. Based on the dynamic model of the rotor UAV, the stability of the whole UAV manipulator control system is improved by using the piecewise cost function, the compression factor particle swarm optimization (PSO) algorithm and the sliding mode PID to establish the sliding mode PID control stability method based on the PSO. Compared with More >

Ying Song^1,2, Jiale Yan^1,2, Shaofan Li^2,*, Zhuang Kang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.121, No.2, pp. 465-492, 2019, DOI:10.32604/cmes.2019.07190

Abstract In the present work, a state-based peridynamics with adaptive particle refinement is proposed to simulate water ice crater formation due to impact loads. A modified Drucker-Prager constitutive model was adopted to model ice and was implemented in the state-based peridynamic equations to analyze the elastic-plastic deformation of ice. In simulations, we use the fracture toughness failure criterion in peridynamics to simulate the quasi-brittle failure of ice. An adaptive particle refinement method in peridynamics was proposed to improve computational efficiency. The results obtained using the peridynamic model were compared with the experiments in previous literatures. It More >

Zhanqi Cheng¹, Dongdong Jin¹, Chengfang Yuan¹, Le Li^1,*

CMES-Computer Modeling in Engineering & Sciences, Vol.121, No.2, pp. 445-464, 2019, DOI:10.32604/cmes.2019.06374

Abstract In the research, the dynamic fracture failure problem of functionally graded materials (FGMs) containing two pre-cracks was analyzed using a bond-based Peridynamic (PD) method numerical model. The two convergence of decreasing the area of PD horizon (δ-convergence) and uniform mesh refinement (m-convergence) were studied. The effects of both crack position and distance between two cracks on crack propagation pattern in FGMs plate under tensile loads are studied. Furthermore, the effects of different gradient patterns on the dynamic propagation of cracks in FGMs are also investigated. The simulate results suggest that the cracks positions and the More >

Jidong Zhang^1,2,*, Wentao Sui², Jaspreet Dhupia³

Sound & Vibration, Vol.53, No.2, pp. 38-49, 2019, DOI:10.32604/sv.2019.04362

Abstract Occurrence of gear rattle in transmission systems can result in severe vibration and noise, which in applications such as automobiles is an important source of user discomfort. As a result , the reduction of the rattling noise has attracted lot of concerns. The rattling noise level is affected by several gearbox parameters, an understanding of which is essential to prevent the expensive design modifications at later stages of product development. To develop such understanding at the gearbox design stage, this paper analytically evaluates the gear parameters’ effect on the root mean square of the wheel More >

Yinhu Qiao^1,*, Chunyan Zhang¹, Jiang Han²

Sound & Vibration, Vol.53, No.1, pp. 14-24, 2019, DOI:10.32604/sv.2019.04120

Abstract This paper presents a theoretical analysis of vibration control technology of wind turbine blades made of piezoelectric intelligent structures. The design of the blade structure, which is made from piezoelectric material, is approximately equivalent to a flat shell structure. The differential equations of piezoelectric shallow shells for vibration control are derived based on piezoelectric laminated shell theory. On this basis, wind turbine blades are simplified as elastic piezoelectric laminated shells. We establish the electromechanical coupling system dynamic model of intelligent structures and the dynamic equation of composite piezoelectric flat shell structures by analyzing simulations of More >

Zhanqi Cheng¹, Zhenyu Wang¹, Zhongtao Luo^2,*

CMES-Computer Modeling in Engineering & Sciences, Vol.118, No.3, pp. 509-527, 2019, DOI:10.31614/cmes.2019.04339

Abstract In this work, a bond-based peridynamics (PD) model was built to analyze the dynamic fracture of shale material. Both the the convergence studies and the result of dynamic crack propagation were presented. As well-known, crack propagation, aggregation, and bifurcation play an critical role in the failure analysis of brittle materials such as shale. The dynamic crack propagation and branching analysis of shale by using the PD method were discussed. Firstly, the valid and accuracy of the PD model for the rock materials was verified by comparing with the existed numerical results. Secondly, we discussed the More >

Marziyeh Eftekhari¹, Omid Vahidi^1,*

CMES-Computer Modeling in Engineering & Sciences, Vol.114, No.2, pp. 153-171, 2018, DOI:10.3970/cmes.2018.114.153

Abstract Various drugs are used to maintain normoglycemia in subjects with type 2 diabetes mellitus. The combination of the drugs from different classes in one single tablet may enhance the effectiveness of the anti-diabetic drugs. To investigate the impact of combining drugs on the glucose regulation of subjects with type 2 diabetes, we propose a pharmacokinetic/pharmacodynamics (PK/PD) mathematical modeling approach for a combination of metformin and vildagliptin drugs. In the proposed modeling approach, two separate PK models representing oral administration of metformin and vildagliptin for diabetic subjects are interconnected to a PD model comprising a detailed More >

Sanghyun Shim, Kwangjin Kim, Sangchul Lee, Sangho Ko, Jayoung Kang, Dongyoung Rew, Gwanghyeok Ju

The International Conference on Computational & Experimental Engineering and Sciences, Vol.19, No.3, pp. 73-74, 2011, DOI:10.3970/icces.2011.019.073

Abstract The aim of this paper is to discuss the main issues related to modeling and simulation of the Korean lunar module. Lunar module usually consists of a rigid platform, attitude control actuators and a fuel tank. For dynamical modeling, we first assumed the lunar module as a rigid body and derived equations of motion by considering allocation of reaction thrusters and reaction wheel assembly(RWA). Fuel sloshing in lunar module and its influence on attitude dynamics are an important issue in the research field of space technology. In order to include the effect of fuel sloshing More >

Delfim Soares Jr.¹

CMES-Computer Modeling in Engineering & Sciences, Vol.76, No.1, pp. 61-82, 2011, DOI:10.3970/cmes.2011.076.061

Abstract This work proposes an iterative procedure to analyse pore-dynamic models discretized by time-domain Meshless Local Petrov-Galerkin formulations. By considering an iterative procedure based on a successive renew of variables, each phase of the coupled problem in focus can be treated separately, uncoupling the governing equations of the model. Thus, smaller and better conditioned systems of equations are obtained, rendering a more attractive methodology. A relaxation parameter is introduced here in order to improve the efficiency of the iterative procedure and an expression to compute optimal values for the relaxation parameter is discussed. Linear and nonlinear More >

Jinling Long^1,2, Bingang Xu^1,3, Xiaoming Tao¹

CMES-Computer Modeling in Engineering & Sciences, Vol.72, No.4, pp. 273-298, 2011, DOI:10.3970/cmes.2011.072.273

Abstract Moving slender threadline structures are widely used in various engineering fields. The dynamics of these systems is sometimes time dependent but in most cases follows a periodic pattern, and slender yarn motion in textile engineering is a typical problem of this category. In the present paper, we propose a nonlinear approach to model the dynamic behavior of slender threadline structures with a real example in the analysis of slender yarn motion in spinning. Moving boundary conditions of yarn are derived and a consequence of the perturbation analysis for the dimensionless governing equations provides the zero More >