A novel nonlinear dynamics model is developed in this paper to describe the static and dynamic nonlinear behaviors of a rod pendulum partially immersed in still water. The pendulum is hinged above the water level and subject to nonlinear gravity, hydrostatic, and hydrodynamic loads, all of which are incorporated into the system dynamics. The nonlinear static behavior and stability of the pendulum have been characterized by analyzing the fixed points. It is found that Pitchfork bifurcation governs the relationship between the rod density (the control parameter) and the static equilibrium angle. The pendulum's nonlinear response to external harmonic torque is obtained using Harmonic Balance Method (HBM). The influence of system parameters, including hinge height, rod diameter, and rod density, on the nonlinear frequency response is examined. Upon altering the system parameters, particularly the rod density, it is found that the system exhibits either a softening or a hardening effect.
{"title":"Nonlinear Static and Dynamic Responses of a Floating Rod Pendulum","authors":"M. K. Al-Solihat","doi":"10.1115/1.4065899","DOIUrl":"https://doi.org/10.1115/1.4065899","url":null,"abstract":"\u0000 A novel nonlinear dynamics model is developed in this paper to describe the static and dynamic nonlinear behaviors of a rod pendulum partially immersed in still water. The pendulum is hinged above the water level and subject to nonlinear gravity, hydrostatic, and hydrodynamic loads, all of which are incorporated into the system dynamics. The nonlinear static behavior and stability of the pendulum have been characterized by analyzing the fixed points. It is found that Pitchfork bifurcation governs the relationship between the rod density (the control parameter) and the static equilibrium angle. The pendulum's nonlinear response to external harmonic torque is obtained using Harmonic Balance Method (HBM). The influence of system parameters, including hinge height, rod diameter, and rod density, on the nonlinear frequency response is examined. Upon altering the system parameters, particularly the rod density, it is found that the system exhibits either a softening or a hardening effect.","PeriodicalId":506262,"journal":{"name":"Journal of Computational and Nonlinear Dynamics","volume":" 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141676350","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The paper presents a defect correction method to solve singularly perturbed problems with discontinuous coefficient and point source. The method combines an inexpensive, lower-order stable, upwind difference scheme and a higher-order, less stable central difference scheme over a layer-adapted mesh. The mesh is designed so that most mesh points remain in the regions with rapid transitions. A posteriori error analysis is presented. The proposed numerical method is analysed for consistency, stability and convergence. The error estimates of the proposed numerical method satisfy parameter-uniform second-order convergence on the layer-adapted grid. The convergence obtained is optimal because it is free from any logarithmic term. The numerical analysis confirms the theoretical error analysis.
{"title":"A Posteriori Error Analysis of Defect Correction Method for Singular Perturbation Problems with Discontinuous Coefficient and Point Source","authors":"Aditya Kaushik, Shivani Jain","doi":"10.1115/1.4065900","DOIUrl":"https://doi.org/10.1115/1.4065900","url":null,"abstract":"\u0000 The paper presents a defect correction method to solve singularly perturbed problems with discontinuous coefficient and point source. The method combines an inexpensive, lower-order stable, upwind difference scheme and a higher-order, less stable central difference scheme over a layer-adapted mesh. The mesh is designed so that most mesh points remain in the regions with rapid transitions. A posteriori error analysis is presented. The proposed numerical method is analysed for consistency, stability and convergence. The error estimates of the proposed numerical method satisfy parameter-uniform second-order convergence on the layer-adapted grid. The convergence obtained is optimal because it is free from any logarithmic term. The numerical analysis confirms the theoretical error analysis.","PeriodicalId":506262,"journal":{"name":"Journal of Computational and Nonlinear Dynamics","volume":" 22","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141676010","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xiangyu Du, Min Xiao, Yifeng Luan, Jie Ding, Leszek Rutkowski
In neural networks, the states of neural networks often exhibit significant spatio-temporal heterogeneity due to the diffusion effect of electrons and differences in the concentration of neurotransmitters. One of the macroscopic reflections of this time-spatial inhomogeneity is Turing pattern. However, most current research in reaction-diffusion neural networks has focused only on one-dimensional location information, and the remaining results considering two-dimensional location information are still limited to the case of two neurons. In this paper, we conduct the dynamic analysis and optimal control of a delayed reaction-diffusion neural network model with bi-directional loop structure. First, several mathematical descriptions are given for the proposed neural network model and the full-dimensional partial differential proportional-derivative (PD) controller is introduced. Second, by analyzing the characteristic equation, the conditions for Hopf bifurcation and Turing instability of the controlled network model are obtained. Furthermore, the amplitude equation of the controlled neural network is obtained based on the multi-scale analysis method. Subsequently, we determine the key parameters affecting the formation of Turing pattern depending on the amplitude equation. Finally, multiple sets of computer simulations are carried out to support our theoretical results. It is found that the diffusion coefficients and time delays have significant effects on spatio-temporal dynamics of neural networks. Moreover, after reasonable parameter proportioning, the full-dimensional PD control method can alleviate the spatial heterogeneity caused by diffusion projects and time delays.
{"title":"Full-Dimensional PD Control Technique for Turing Pattern and Bifurcation of Delayed Reaction-Diffusion Bi-Directional Ring Neural Networks","authors":"Xiangyu Du, Min Xiao, Yifeng Luan, Jie Ding, Leszek Rutkowski","doi":"10.1115/1.4065881","DOIUrl":"https://doi.org/10.1115/1.4065881","url":null,"abstract":"\u0000 In neural networks, the states of neural networks often exhibit significant spatio-temporal heterogeneity due to the diffusion effect of electrons and differences in the concentration of neurotransmitters. One of the macroscopic reflections of this time-spatial inhomogeneity is Turing pattern. However, most current research in reaction-diffusion neural networks has focused only on one-dimensional location information, and the remaining results considering two-dimensional location information are still limited to the case of two neurons. In this paper, we conduct the dynamic analysis and optimal control of a delayed reaction-diffusion neural network model with bi-directional loop structure. First, several mathematical descriptions are given for the proposed neural network model and the full-dimensional partial differential proportional-derivative (PD) controller is introduced. Second, by analyzing the characteristic equation, the conditions for Hopf bifurcation and Turing instability of the controlled network model are obtained. Furthermore, the amplitude equation of the controlled neural network is obtained based on the multi-scale analysis method. Subsequently, we determine the key parameters affecting the formation of Turing pattern depending on the amplitude equation. Finally, multiple sets of computer simulations are carried out to support our theoretical results. It is found that the diffusion coefficients and time delays have significant effects on spatio-temporal dynamics of neural networks. Moreover, after reasonable parameter proportioning, the full-dimensional PD control method can alleviate the spatial heterogeneity caused by diffusion projects and time delays.","PeriodicalId":506262,"journal":{"name":"Journal of Computational and Nonlinear Dynamics","volume":"72 s323","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141682999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The main objective of this work is to use the Time Variational Method (TVM), a semi-analytical approach to evaluate steady-state responses in the time domain for Absolute Nodal Coordinate Formulation (ANCF) modeled systems. The gradient-deficient ANCF beam element's performance is demonstrated for a highly flexible cantilever beam under gravity and impulse loading, with comparisons to experiments. The damping behavior is compared for the Rayleigh proportional and the Navier-Stokes damping model for a gradient-deficient ANCF beam element. Classical FEM beam formulation's shortcomings in predicting large deflections of thin, flexible cantilever beams are highlighted. Unlike the Harmonic Balance Method, TVM reduces the computational time for harmonic response evaluation compared to numerical integration techniques and handles nonlinear forces in the time domain. The harmonic response is evaluated by exciting the cantilever beam in the linear region for both experiments and TVM computations.
{"title":"Harmonic Response of a Highly Flexible Thin Long Cantilever Beam: A Semi-Analytical Approach in Time-Domain with ANCF Modeling and Experimental Validation","authors":"A. R. Renjith, Reek Jyoti Hati, I. R. P. Krishna","doi":"10.1115/1.4065880","DOIUrl":"https://doi.org/10.1115/1.4065880","url":null,"abstract":"\u0000 The main objective of this work is to use the Time Variational Method (TVM), a semi-analytical approach to evaluate steady-state responses in the time domain for Absolute Nodal Coordinate Formulation (ANCF) modeled systems. The gradient-deficient ANCF beam element's performance is demonstrated for a highly flexible cantilever beam under gravity and impulse loading, with comparisons to experiments. The damping behavior is compared for the Rayleigh proportional and the Navier-Stokes damping model for a gradient-deficient ANCF beam element. Classical FEM beam formulation's shortcomings in predicting large deflections of thin, flexible cantilever beams are highlighted. Unlike the Harmonic Balance Method, TVM reduces the computational time for harmonic response evaluation compared to numerical integration techniques and handles nonlinear forces in the time domain. The harmonic response is evaluated by exciting the cantilever beam in the linear region for both experiments and TVM computations.","PeriodicalId":506262,"journal":{"name":"Journal of Computational and Nonlinear Dynamics","volume":" 19","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141680381","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The Haar wavelet collocation method, a wavelet technique, is discussed in this article to examine the mathematical model of Hepatitis B virus infection. We took into account the HB virus, cytotoxic T lymphocytes (CTL) immune response, birth rate, death rate, and infected and uninfected hepatocytes to identify the dynamics of the hepatitis B virus infection. An ordinary differential equation (ODE) system that is nonlinear makes up this model. Using this method, the Hepatitis B Virus model can be solved by expressing each dependent variable as a Haar wavelet and then converting the system of ordinary differential equations into a system of nonlinear algebraic equations. The unknown coefficient values are thought to be extracted using the collocation procedure and the Newton-Raphson method. Tables and graphs are used to illustrate the characteristics of the Hepatitis B virus. The obtained results show that the current approach outperforms other approaches found in the literature in terms of accuracy. Mathematica software is utilized to obtain numerical results and nature.
本文讨论了小波技术中的哈小波配位法，以研究乙型肝炎病毒感染的数学模型。我们考虑了 HB 病毒、细胞毒性 T 淋巴细胞（CTL）免疫反应、出生率、死亡率、感染和未感染肝细胞等因素，以确定乙型肝炎病毒感染的动态变化。该模型由一个非线性常微分方程（ODE）系统构成。使用这种方法，可以通过将每个因变量表示为 Haar 小波，然后将常微分方程系统转换为非线性代数方程系统来求解乙型肝炎病毒模型。未知系数值的提取可使用配位程序和牛顿-拉斐森方法。用表格和图表说明了乙型肝炎病毒的特征。得出的结果表明，目前的方法在准确性方面优于文献中发现的其他方法。Mathematica 软件用于获得数值结果和性质。
{"title":"Haar Wavelet Approach for the Mathematical Model On Hepatitis B Virus","authors":"K. S., Y. R","doi":"10.1115/1.4065843","DOIUrl":"https://doi.org/10.1115/1.4065843","url":null,"abstract":"\u0000 The Haar wavelet collocation method, a wavelet technique, is discussed in this article to examine the mathematical model of Hepatitis B virus infection. We took into account the HB virus, cytotoxic T lymphocytes (CTL) immune response, birth rate, death rate, and infected and uninfected hepatocytes to identify the dynamics of the hepatitis B virus infection. An ordinary differential equation (ODE) system that is nonlinear makes up this model. Using this method, the Hepatitis B Virus model can be solved by expressing each dependent variable as a Haar wavelet and then converting the system of ordinary differential equations into a system of nonlinear algebraic equations. The unknown coefficient values are thought to be extracted using the collocation procedure and the Newton-Raphson method. Tables and graphs are used to illustrate the characteristics of the Hepatitis B virus. The obtained results show that the current approach outperforms other approaches found in the literature in terms of accuracy. Mathematica software is utilized to obtain numerical results and nature.","PeriodicalId":506262,"journal":{"name":"Journal of Computational and Nonlinear Dynamics","volume":"31 9","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141709978","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We present a tensor-based method for model selection which identifies the unknown partial differential equation that governs a dynamical system using only spatiotemporal measurements. The method circumvents a disadvantage of standard matrix-based methods which typically have large storage consumption. Using a recently developed multidimensional approximation of nonlinear dynamical systems, we collect the nonlinear and partial derivative terms of the measured data and construct a low-rank dictionary tensor in the tensor-train format. A tensor-based linear regression problem is then built, which balances the learning accuracy, model complexity, and computational efficiency. An algebraic expression of the unknown equations can be extracted. Numerical results are demonstrated on datasets generated by the wave equation, the Burgers' equation, and a few parametric partial differential equations.
{"title":"Tensor-Based Data-Driven Identification of Partial Differential Equations","authors":"Wanting Lin, Xiaofan Lu, Linan Zhang","doi":"10.1115/1.4065691","DOIUrl":"https://doi.org/10.1115/1.4065691","url":null,"abstract":"\u0000 We present a tensor-based method for model selection which identifies the unknown partial differential equation that governs a dynamical system using only spatiotemporal measurements. The method circumvents a disadvantage of standard matrix-based methods which typically have large storage consumption. Using a recently developed multidimensional approximation of nonlinear dynamical systems, we collect the nonlinear and partial derivative terms of the measured data and construct a low-rank dictionary tensor in the tensor-train format. A tensor-based linear regression problem is then built, which balances the learning accuracy, model complexity, and computational efficiency. An algebraic expression of the unknown equations can be extracted. Numerical results are demonstrated on datasets generated by the wave equation, the Burgers' equation, and a few parametric partial differential equations.","PeriodicalId":506262,"journal":{"name":"Journal of Computational and Nonlinear Dynamics","volume":"113 33","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141362024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Efficient passive vibration absorption can prevent the failure of systems without requiring sensors or energy sources. Nonlinear energy sinks (NES) have gained popularity as passive vibration absorbers due to their targeted energy transfer (TET) mechanisms that extract and dissipate vibrational energy over broad frequency ranges. In this work, the vibration suppression performance of a novel bistable rotary nonlinear energy sink (BRNES) is studied numerically in the cases of impulse and harmonic excitation. The BRNES consists of a secondary mass that connects to the primary system by a rigid arm and spring that pivot at each connection point. The spring produces an irrational nonlinear restoring force that introduces bistability and favorable oscillatory TET mechanisms. The BRNES outperforms the traditional rotary NES and, in some cases, even the bistable NES. Moreover, unlike most NESs restricted to rectilinear motion, the BRNES is efficient at multiple orientations, thus demonstrating its potential to passively suppress vibrations in any in-plane direction over broad excitation magnitude and frequency ranges.
高效的被动振动吸收可防止系统发生故障，而无需传感器或能源。非线性能量吸收器（NES）作为被动振动吸收器已广为流行，因为其定向能量转移（TET）机制可在宽广的频率范围内提取和耗散振动能量。在这项工作中，我们通过数值方法研究了新型双稳态旋转非线性能量吸收器（BRNES）在脉冲和谐波激励情况下的振动抑制性能。双稳态旋转非线性能量沉降器由一个副质量块组成，副质量块通过刚性臂和弹簧与主系统相连，每个连接点都有枢轴。弹簧产生的非理性非线性恢复力引入了双稳态和有利的振荡 TET 机制。BRNES 的性能优于传统的旋转式 NES，在某些情况下甚至优于双稳态 NES。此外，与大多数仅限于直线运动的 NES 不同，BRNES 在多个方向上都很有效，从而证明了其在宽激励幅度和频率范围内被动抑制任何平面方向振动的潜力。
{"title":"Irrational Nonlinearity Enhances the Targeted Energy Transfer in a Rotary Nonlinear Energy Sink","authors":"Collin Treacy, Dalton L. Stein, D. Chelidze","doi":"10.1115/1.4065193","DOIUrl":"https://doi.org/10.1115/1.4065193","url":null,"abstract":"\u0000 Efficient passive vibration absorption can prevent the failure of systems without requiring sensors or energy sources. Nonlinear energy sinks (NES) have gained popularity as passive vibration absorbers due to their targeted energy transfer (TET) mechanisms that extract and dissipate vibrational energy over broad frequency ranges. In this work, the vibration suppression performance of a novel bistable rotary nonlinear energy sink (BRNES) is studied numerically in the cases of impulse and harmonic excitation. The BRNES consists of a secondary mass that connects to the primary system by a rigid arm and spring that pivot at each connection point. The spring produces an irrational nonlinear restoring force that introduces bistability and favorable oscillatory TET mechanisms. The BRNES outperforms the traditional rotary NES and, in some cases, even the bistable NES. Moreover, unlike most NESs restricted to rectilinear motion, the BRNES is efficient at multiple orientations, thus demonstrating its potential to passively suppress vibrations in any in-plane direction over broad excitation magnitude and frequency ranges.","PeriodicalId":506262,"journal":{"name":"Journal of Computational and Nonlinear Dynamics","volume":"123 39","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140379881","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This work investigates the effectiveness of a passive vibration control device to minimize the amplitude of vibrations from a handheld impact machine (HHIM) transmitted to a hand-arm system. For this purpose, we employ a simplified lumped parameter model of an HHIM and the hand-arm system consisting of lumped masses, springs, and viscous dampers. For a better understanding of the system dynamics, we use a vibro-impact model for a more accurate representation of HHIM-ground interactions. We then examine the effectiveness of a cubic nonlinear vibration absorber in minimizing these undesirable vibrations via a nonlinear bifurcation analysis of the system. A parametric study on the numerical bifurcation analysis of the system reveals the criticality of different design parameters of the proposed nonlinear vibration absorber on the system dynamics. Our findings demonstrate that an appropriate selection of absorber parameters could significantly change the amplitude and the periodicity of vibrations transmitted to the hand. Furthermore, we observe the existence of complex motions such as period-2, period-4, and chaotic attractors in the system for the given values of the absorber and operating parameters.
{"title":"Hand Vibration Reduction Using Nonlinear Vibration Absorber for the Vibro-Impact Hammer Model","authors":"Oreoluwa Alabi, S. K. Gupta, Oumar Barry","doi":"10.1115/1.4065192","DOIUrl":"https://doi.org/10.1115/1.4065192","url":null,"abstract":"\u0000 This work investigates the effectiveness of a passive vibration control device to minimize the amplitude of vibrations from a handheld impact machine (HHIM) transmitted to a hand-arm system. For this purpose, we employ a simplified lumped parameter model of an HHIM and the hand-arm system consisting of lumped masses, springs, and viscous dampers. For a better understanding of the system dynamics, we use a vibro-impact model for a more accurate representation of HHIM-ground interactions. We then examine the effectiveness of a cubic nonlinear vibration absorber in minimizing these undesirable vibrations via a nonlinear bifurcation analysis of the system. A parametric study on the numerical bifurcation analysis of the system reveals the criticality of different design parameters of the proposed nonlinear vibration absorber on the system dynamics. Our findings demonstrate that an appropriate selection of absorber parameters could significantly change the amplitude and the periodicity of vibrations transmitted to the hand. Furthermore, we observe the existence of complex motions such as period-2, period-4, and chaotic attractors in the system for the given values of the absorber and operating parameters.","PeriodicalId":506262,"journal":{"name":"Journal of Computational and Nonlinear Dynamics","volume":"122 29","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140380046","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Reviewer's Recognition","authors":"","doi":"10.1115/1.4064764","DOIUrl":"https://doi.org/10.1115/1.4064764","url":null,"abstract":"","PeriodicalId":506262,"journal":{"name":"Journal of Computational and Nonlinear Dynamics","volume":"2011 33","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140416625","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hiroki Yamashita, J. E. Martin, Nathan Tison, Arkady Grunin, P. Jayakumar, Hiroyuki Sugiyama
In this study, a data-driven hydrodynamics model is proposed to enable quick prediction of vehicle mobility in shallow water, considering the effect of tire-soil interaction. To this end, a high-fidelity coupled vehicle-water interaction model using computational fluid dynamics (CFD) and multibody dynamics (MBD) solvers is developed to characterize the hydrodynamic loads exerted on a vehicle operated in shallow water, and it is used to generate training data for the data-driven hydrodynamics model. To account for the history-dependent hydrodynamic behavior, a Long Short-Term Memory (LSTM) neural network is introduced to incorporate effects of the historical variation of vehicle motion states as the input to the data-driven model, and it is used to predict hydrodynamic loads online exerted on vehicle components in the MBD mobility simulation. The impacts of hydrodynamic loads on the vehicle mobility capability in shallow water are examined for different water depths and incoming flow speeds using the high-fidelity coupled CFD-MBD model. Furthermore, it is demonstrated that the vehicle-water interaction behavior in scenarios not considered in the training data can be predicted using the proposed LSTM data-driven hydrodynamics model. However, the use of non-LSTM layers, which do not account for the sequential variation of vehicle motion states as the input, leads to an inaccurate prediction. A substantial computational speedup is achieved with the proposed LSTM-MBD vehicle-water interaction model while ensuring accuracy, compared to the computationally expensive high-fidelity coupled CFD-MBD model.
{"title":"Modeling of Vehicle Mobility in Shallow Water with Data-Driven Hydrodynamics Model","authors":"Hiroki Yamashita, J. E. Martin, Nathan Tison, Arkady Grunin, P. Jayakumar, Hiroyuki Sugiyama","doi":"10.1115/1.4064971","DOIUrl":"https://doi.org/10.1115/1.4064971","url":null,"abstract":"\u0000 In this study, a data-driven hydrodynamics model is proposed to enable quick prediction of vehicle mobility in shallow water, considering the effect of tire-soil interaction. To this end, a high-fidelity coupled vehicle-water interaction model using computational fluid dynamics (CFD) and multibody dynamics (MBD) solvers is developed to characterize the hydrodynamic loads exerted on a vehicle operated in shallow water, and it is used to generate training data for the data-driven hydrodynamics model. To account for the history-dependent hydrodynamic behavior, a Long Short-Term Memory (LSTM) neural network is introduced to incorporate effects of the historical variation of vehicle motion states as the input to the data-driven model, and it is used to predict hydrodynamic loads online exerted on vehicle components in the MBD mobility simulation. The impacts of hydrodynamic loads on the vehicle mobility capability in shallow water are examined for different water depths and incoming flow speeds using the high-fidelity coupled CFD-MBD model. Furthermore, it is demonstrated that the vehicle-water interaction behavior in scenarios not considered in the training data can be predicted using the proposed LSTM data-driven hydrodynamics model. However, the use of non-LSTM layers, which do not account for the sequential variation of vehicle motion states as the input, leads to an inaccurate prediction. A substantial computational speedup is achieved with the proposed LSTM-MBD vehicle-water interaction model while ensuring accuracy, compared to the computationally expensive high-fidelity coupled CFD-MBD model.","PeriodicalId":506262,"journal":{"name":"Journal of Computational and Nonlinear Dynamics","volume":"758 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140416942","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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