Yuantian Qin^1,2, Yucheng Zhang^1,*, Vadim V. Silberschmidt²

CMES-Computer Modeling in Engineering & Sciences, Vol.139, No.3, pp. 2865-2891, 2024, DOI:10.32604/cmes.2024.046113 - 11 March 2024

Abstract This paper proposes a novel approach for identifying distributed dynamic loads in the time domain. Using polynomial and modal analysis, the load is transformed into modal space for coefficient identification. This allows the distributed dynamic load with a two-dimensional form in terms of time and space to be simultaneously identified in the form of modal force, thereby achieving dimensionality reduction. The Impulse-based Force Estimation Algorithm is proposed to identify dynamic loads in the time domain. Firstly, the algorithm establishes a recursion scheme based on convolution integral, enabling it to identify loads with a long history More >

David Tae, Kumar K. Tamma^*

CMES-Computer Modeling in Engineering & Sciences, Vol.135, No.2, pp. 843-885, 2023, DOI:10.32604/cmes.2023.023071 - 27 October 2022

Abstract We propose a novel computational framework that is capable of employing different time integration algorithms and different space discretized methods such as the Finite Element Method, particle methods, and other spatial methods on a single body sub-divided into multiple subdomains. This is in conjunction with implementing the well known Generalized Single Step Single Solve (GS4) family of algorithms which encompass the entire scope of Linear Multistep algorithms that have been developed over the past 50 years or so and are second order accurate into the Differential Algebraic Equation framework. In the current state of technology,… More >

S. Pradeepkumar^*, P. Nagaraj

Sound & Vibration, Vol.56, No.3, pp. 221-233, 2022, DOI:10.32604/sv.2022.014889 - 10 August 2022

Abstract Vibrational characteristics in small horizontal axis wind turbine system are presented in this study with a system concept called tactile response and substructuring. The main focus is on managing the dynamic properties like vibration, noise, and harshness that occur during the operational mode. Tactile response is defined as the response of subsystem which is induced when a human body touches a vibrating system. Sub structuring is a computational method used to reduce the dynamic behavior of a large complex system with a smaller number of degrees of freedom without disturbing the mesh size of the… More >

Carlos A. Felippa^*

CMES-Computer Modeling in Engineering & Sciences, Vol.129, No.3, pp. 1209-1241, 2021, DOI:10.32604/cmes.2021.016803 - 25 November 2021

Abstract This paper considers Lagrangian finite elements for structural dynamics constructed with cubic displacement shape functions. The method of templates is used to investigate the construction of accurate mass-stiffness pairs. This method introduces free parameters that can be adjusted to customize elements according to accuracy and rank-sufficiency criteria. One- and two-dimensional Lagrangian cubic elements with only translational degrees of freedom (DOF) carry two additional nodes on each side, herein called side nodes or SN. Although usually placed at the third-points, the SN location may be adjusted within geometric limits. The adjustment effect is studied in detail… More >

Yi Ji^1,2, Yufeng Xing^1,*

CMES-Computer Modeling in Engineering & Sciences, Vol.126, No.2, pp. 549-575, 2021, DOI:10.32604/cmes.2021.014244 - 21 January 2021

Abstract Based on the weighted residual method, a single-step time integration algorithm with higher-order accuracy and unconditional stability has been proposed, which is superior to the second-order accurate algorithms in tracking long-term dynamics. For improving such a higher-order accurate algorithm, this paper proposes a two sub-step higher-order algorithm with unconditional stability and controllable dissipation. In the proposed algorithm, a time step interval [tk, tk + h] where h stands for the size of a time step is divided into two sub-steps [tk, tk + γh] and [tk + γh, tk + h]. A non-dissipative fourth-order algorithm is used in the rst… More >

Sun-Beom Kwon¹, Jae-Myung Lee^1,*

CMES-Computer Modeling in Engineering & Sciences, Vol.118, No.1, pp. 41-89, 2019, DOI:10.31614/cmes.2019.03879

Abstract A direct time integration scheme based on Gauss-Legendre quadrature is proposed to solve problems in linear structural dynamics. The proposed method is a one-parameter non-dissipative scheme. Improved stability, accuracy, and dispersion characteristics are achieved using appropriate values of the parameter. The proposed scheme has second-order accuracy with and without physical damping. Moreover, its stability, accuracy, and dispersion are analyzed. In addition, its performance is demonstrated by the two-dimensional scalar wave problem, the single-degree-of-freedom problem, two degrees-of-freedom spring system, and beam with boundary constraints. The wave propagation problem is solved in the high frequency wave regime More >

Zhiqiang Ma^1,2, Lingshuang Kong^1,2, Xianlong Jin^1,2,*

CMES-Computer Modeling in Engineering & Sciences, Vol.116, No.1, pp. 51-67, 2018, DOI:10.31614/cmes.2018.01739

Abstract Many engineering applications need to analyse the system dynamics on the macro and micro level, which results in a larger computational effort. An explicit-implicit asynchronous step algorithm is introduced to solve the structural dynamics in multi-scale both the space domain and time domain. The discrete FEA model is partitioned into explicit and implicit parts using the nodal partition method. Multiple boundary node method is adopted to handle the interface coupled problem. In coupled region, the implicit Newmark coupled with an explicit predictor corrector Newmark whose predictive wave propagates into the implicit mesh. During the explicit More >

Kemei Pei^1,*, Yueben Dong¹, Lei Chen¹

CMC-Computers, Materials & Continua, Vol.55, No.1, pp. 189-200, 2018, DOI:10.3970/cmc.2018.055.189

Abstract Raman (resonance Raman, FT-Raman), IR and UV-visible spectroscopy and quantum chemistry calculations were used to investigate the photodissociation dynamics of furfural in S₂ state. The resonance Raman(RR) spectra indicate that the photorelaxation dynamics for the S₀→S₂ excited state is predominantly along nine motions: C=O stretch ν₅ (1667 cm^-1), ring C=C antisymmetric stretch ν₆ (1570 cm^-1), ring C=C symmetric stretch ν₇ (1472 cm^-1), C2-O6-C5 symmetric stretch/C1-H8 rock in plane ν₈ (1389 cm^-1), C3-C4 stretch/ C1-H8 rock in plane ν₉ (1370 cm^-1), C5-O6 stretch in plane ν₁₂ (1154 cm^-1), ring breath ν₁₃ (1077 cm^-1), C3-C4 stretch ν₁₄ (1020 cm^-1), C3-C2-O6 symmetric stretch ν₁₆ (928 cm^-1 ). Stable More >

Kazem Hejranfar¹, Mohammad-Hadi Azampour¹

CMES-Computer Modeling in Engineering & Sciences, Vol.106, No.6, pp. 395-439, 2015, DOI:10.3970/cmes.2015.106.395

Abstract In this study, cell-centered (CC) and cell-vertex (CV) finite volume (FV) approaches are applied and assessed for the simulation of two-dimensional structural dynamics on arbitrary quadrilateral grids. For the calculation of boundary nodes’ displacement in the CC FV approach, three methods are employed. The first method is a simple linear regression of displacement of boundary nodes from the displacement of interior cell centers. In the second method, an extrapolation technique is applied for this purpose and, in the third method; the line boundary cell technique is incorporated into the solution algorithm in an explicit manner.… More >

K.Willner ¹

CMES-Computer Modeling in Engineering & Sciences, Vol.48, No.3, pp. 303-336, 2009, DOI:10.3970/cmes.2009.048.303

Abstract The dynamic behavior of structures with joints is strongly influenced by the constitutive behavior within the contact areas. In this paper the influence of an elaborate constitutive contact model based on a rough surface model is investigated. The contact model is able to describe several effects like pressure dependent contact stiffness in normal and tangential direction as well as microslip effects. The corresponding constitutive contact laws are implemented in a finite element code. Numerical simulations are compared to experimental results of a clamped double-beam experiment. More >