Surkay D. Akbarov^1,2,*, Emin T. Bagirov²

CMES-Computer Modeling in Engineering & Sciences, Vol.121, No.1, pp. 315-348, 2019, DOI:10.32604/cmes.2019.07732

Abstract The paper deals with the study of the influence of the non-homogeneous pre-stresses in the system consisting of the hollow cylinder and surrounding elastic medium on the frequency response of this system caused by the time-harmonic ring load acting in the interior of the cylinder. The axisymmetric problem is considered and it is assumed that in the initial state, the system is compressed in the radial direction with homogeneously distributed static forces as a result of which, non-homogeneous pre-stresses (or initial stresses) appear in that. It is also assumed that after these pre-stresses appear in… More >

Lizhong Jiang^1,2, Xilin Chai^1,2, Zhihua Tan^1,2, Wangbao Zhou^1,2,*, Yulin Feng^1,2, Zhipeng Lai^1,2, Lan Zheng^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.121, No.1, pp. 291-314, 2019, DOI:10.32604/cmes.2019.07805

Abstract In order to study the dynamic characteristics of a simply supported double-beam system under a moving mass, the system of fourth-order dynamic partial differential equations of a simply supported double-beam system was transformed into a system of second-order dynamic ordinary differential equations relative to time coordinates by performing the finite sin-Fourier Transform relative to space coordinates. And the analytical solution of the dynamic response of the simply supported double-beam system under a moving mass was obtained by solving the system of dynamic ordinary differential equations. The analytical method and ANSYS numerical method were used to… More >

Yan Liang^1,*, Jialei Yan¹, Zhanqi Cheng^1,*, Huai Chen¹, Ruimin Mao¹

CMES-Computer Modeling in Engineering & Sciences, Vol.121, No.1, pp. 177-214, 2019, DOI:10.32604/cmes.2019.07141

Abstract An offshore long-span continuous rigid-frame bridge is taken as an example to study the effect of degradation of bond-slip behavior on the seismic performance of bridges in an offshore environment during a service period. On the basis of a numerical simulation analysis using the OpenSeeS platform, the influence of durability degradation of concrete carbonization, steel corrosion, and degradation of bond-slip performance is considered collectively using incremental dynamic analysis method to examine the time-varying seismic fragility of the offshore bridge. Results show that when bond slip is considered, the exceedance probability of the bridge components and the… More >

Selma B. Jaconis^1,*, Augusto T. Morita², Paulo L. A. Coutinho³, Suzana Borschiver¹

Journal of Renewable Materials, Vol.7, No.11, pp. 1221-1230, 2019, DOI:10.32604/jrm.2019.00025 - 14 July 2021

Abstract In recent years environmental and sustainability concerns have impacted the global chemical industry and instituted a rush to produce products from renewable raw materials. This dynamic, complex and turbulent organizational scenario, around themes touching on the issue of sustainable development model, was created involving a large number of different actors: chemical/petrochemical industries, agroindustry companies, oil/gas companies, brand owners and end users, biotechnology startups, governments, universities and society. This paper proposed the application of a structured and dynamic method of technological prediction for biopolymers in three levels: systematic monitoring process, relational database and the “alive” Technology More >

Guangzheng Yu^1,*, Yu Liu^1,2, Bosun Xie¹, Huali Zhou¹

Sound & Vibration, Vol.53, No.4, pp. 151-159, 2019, DOI:10.32604/sv.2019.04644

Abstract To accelerate head-related transfer functions (HRTFs) measurement, two or more independent sound sources are usually employed in the measurement system. However, the multiple scattering between adjacent sound sources may influence the accuracy of measurement. On the other hand, the directivity of sound source could induce measurement error. Therefore, a model consisting of two spherical sound sources with approximate omni-directivity and a rigid-spherical head is proposed to evaluate the errors in HRTF measurement caused by multiple scattering between sources. An example of analysis using multipole re-expansion indicates that the error of ipsilateral HRTFs are within the More >

Yewan Ma, Hansen Chang, Zhaowang Wu, Yanyan Jiang, Juan Li, Xunchang Yin, Quanjin Liu, Lihua Zhang^*

Sound & Vibration, Vol.53, No.4, pp. 139-149, 2019, DOI:10.32604/sv.2019.04622

Abstract The energy of a spring with a well-distributed mass m_s is theoretically studied in this paper. The solution of the wave equation is derived in detail, and then the kinetic energy and potential energy of the spring are studied with the wave equation, as well as the kinetic energy of the oscillating mass M. The kinetic energy and potential energy of the spring, and total energy are numerically simulated for different ratios m_s/M with considering the spring’s mass, which makes the property of energy of the oscillating system understood easily. More >

Mehdi Sarmast^1,*, Hamed Ghafari², Jan R. Wright³

Sound & Vibration, Vol.53, No.3, pp. 75-95, 2019, DOI:10.32604/sv.2019.04193

Abstract One of the practical approaches in identifying structures is the non-linear resonant decay method which identifies a non-linear dynamic system utilizing a model based on linear modal space containing the underlying linear system and a small number of extra terms that exhibit the non-linear effects. In this paper, the method is illustrated in a simulated system and an experimental structure. The main objective of the non-linear resonant decay method is to identify the non-linear dynamic systems based on the use of a multi-shaker excitation using appropriated excitation which is obtained from the force appropriation approach. More >

Tcw Chen¹, Wray Marriott², Ann Nicholson³, Tim Chen⁴, Mars Kmieckowiak⁵, Jcy Chen^6,*

Sound & Vibration, Vol.53, No.2, pp. 29-37, 2019, DOI:10.32604/sv.2019.04224

Abstract In this paper, a method sustaining system stability after decomposition is proposed. Based on the stability criterion derived from the energy function, a set of intelligent controllers is synthesized which is used to maintain the stability of the system. The sustainable stability problem can be reformulated as a Linear Matrix Inequalities (LMI) problem. The key to guaranteeing the stability of the system as a whole is to find a common symmetrically positive definite matrix for all subsystems. Furthermore, the Evolved Bat Algorithm (EBA) is employed to replace the pole assignment method and the conventional mathematical More >

Deshui Xu, Jingtao Du^*, Yuhao Zhao

Sound & Vibration, Vol.53, No.2, pp. 16-28, 2019, DOI:10.32604/sv.2019.04033

Abstract In this paper, an accurate series solution for the longitudinal vibration analysis of elastically coupled nanorods system is established, in which artificial springs are introduced to simulate such general coupling and boundary conditions. Energy formulation is derived for the description of axial dynamics of multiple coupled nanorods based on Eringen nonlocal elasticity. For each nanorod component, its longitudinal vibration displacement function is invariantly assumed as the superposition of Fourier series and boundary smoothed supplementary polynomials, with the aim to make all the spatial differential sufficiently continuous across each rod. All the unknown coefficients are determined… More >

Longqing Zhang¹, Liping Bai^1,*, Xinwei Zhang², Yanghong Zhang², Lei Yang¹, Xiangdu Yan²

CMC-Computers, Materials & Continua, Vol.61, No.2, pp. 817-828, 2019, DOI:10.32604/cmc.2019.06062

Abstract The drawbacks of the traditional multi-hop structure of wireless sensor networks (WSNS) are susceptible to reflection, scattering and diffraction, serious attenuation of signal intensity and phase deviation due to various obstacles in cultivated land environment and mountains. In this paper, the wireless signal intensity is measured and curve fitting is done respectively in both open environment and obstacle-environment with both sending and receiving height of 0 m, 1 m, and 2 m. It is found out that packet loss probability is too high when an obstacle exists. In such a case, unmanned aerial vehicle (UAV) More >