Pub Date : 2025-11-01Epub Date: 2025-06-26DOI: 10.1016/j.ijnonlinmec.2025.105198
Serkan Guler
A novel hybrid control approach has been designed with the primary objective of minimizing vibration amplitude as quickly and effectively as possible, particularly in response to mechanical shocks. The control approach taken in this study is a hybrid methodology based on the integration of the soliton-inspired wave and the conventional Proportional-Integral-Derivative (PID) control technique. The proposed hybrid control approach is compared with the conventional PID control technique considering two-DOF, four-DOF and five-DOF vibratory systems. Mathematical models of these vibratory systems are established and simulated numerically. In these simulations, it was found that the presented control technique further mitigates vibrations than conventional PID. Moreover, to investigate the applicability of the hybrid control methodology in this research to real engineering systems, a half-vehicle model and bolted cantilever beams are considered. Numerical simulation studies are carried out for these two different engineering systems. Through numerical simulation studies conducted on these systems, it was revealed that the proposed hybrid control approach exhibits superior active vibration control performance to the conventional PID method.
{"title":"Soliton inspired hybrid active vibration control method for shock-induced transient vibrations: Numerical perspective","authors":"Serkan Guler","doi":"10.1016/j.ijnonlinmec.2025.105198","DOIUrl":"10.1016/j.ijnonlinmec.2025.105198","url":null,"abstract":"<div><div>A novel hybrid control approach has been designed with the primary objective of minimizing vibration amplitude as quickly and effectively as possible, particularly in response to mechanical shocks. The control approach taken in this study is a hybrid methodology based on the integration of the soliton-inspired wave and the conventional Proportional-Integral-Derivative (PID) control technique. The proposed hybrid control approach is compared with the conventional PID control technique considering two-DOF, four-DOF and five-DOF vibratory systems. Mathematical models of these vibratory systems are established and simulated numerically. In these simulations, it was found that the presented control technique further mitigates vibrations than conventional PID. Moreover, to investigate the applicability of the hybrid control methodology in this research to real engineering systems, a half-vehicle model and bolted cantilever beams are considered. Numerical simulation studies are carried out for these two different engineering systems. Through numerical simulation studies conducted on these systems, it was revealed that the proposed hybrid control approach exhibits superior active vibration control performance to the conventional PID method.</div></div>","PeriodicalId":50303,"journal":{"name":"International Journal of Non-Linear Mechanics","volume":"178 ","pages":"Article 105198"},"PeriodicalIF":2.8,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144522291","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01Epub Date: 2025-07-03DOI: 10.1016/j.ijnonlinmec.2025.105202
Xin Fang , Jianghao Wu , Feng Du
Mechanism bears various types of loads. However, the effect of load type and magnitude on the dynamic characteristics of mechanism is less clear. This study investigates the effect of load force on the dynamic characteristics of planar mechanisms with clearance through theoretical modeling and experimental method. The dynamic model of mechanism with clearance is formulated utilizing the Lagrange multiplier method, incorporating a contact force model based on the Lankarani-Nikravesh and modified Coulomb models. Dynamic analysis of a slider-crank mechanism is conducted, revealing a transition from chaotic to periodic behavior with increasing force magnitude. The findings demonstrate the universal behavior across different load force forms, parametric conditions and topological configurations. Experimental validation is conducted on a multi-link mechanism with clearance joints and shows good agreement with theoretical prediction. A comparative analysis between a ball-plane impact model and the slider-crank mechanism with clearance is performed and the effect of load type and magnitude is analyzed respectively. This finding highlights the critical role of load force in determining the dynamic characteristics of planar multibody systems with clearances, offering valuable insights for designing mechanical systems under diverse load conditions.
{"title":"Load force effect on the dynamic characteristics of planar multibody systems with clearances","authors":"Xin Fang , Jianghao Wu , Feng Du","doi":"10.1016/j.ijnonlinmec.2025.105202","DOIUrl":"10.1016/j.ijnonlinmec.2025.105202","url":null,"abstract":"<div><div>Mechanism bears various types of loads. However, the effect of load type and magnitude on the dynamic characteristics of mechanism is less clear. This study investigates the effect of load force on the dynamic characteristics of planar mechanisms with clearance through theoretical modeling and experimental method. The dynamic model of mechanism with clearance is formulated utilizing the Lagrange multiplier method, incorporating a contact force model based on the Lankarani-Nikravesh and modified Coulomb models. Dynamic analysis of a slider-crank mechanism is conducted, revealing a transition from chaotic to periodic behavior with increasing force magnitude. The findings demonstrate the universal behavior across different load force forms, parametric conditions and topological configurations. Experimental validation is conducted on a multi-link mechanism with clearance joints and shows good agreement with theoretical prediction. A comparative analysis between a ball-plane impact model and the slider-crank mechanism with clearance is performed and the effect of load type and magnitude is analyzed respectively. This finding highlights the critical role of load force in determining the dynamic characteristics of planar multibody systems with clearances, offering valuable insights for designing mechanical systems under diverse load conditions.</div></div>","PeriodicalId":50303,"journal":{"name":"International Journal of Non-Linear Mechanics","volume":"178 ","pages":"Article 105202"},"PeriodicalIF":2.8,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144571843","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01Epub Date: 2025-06-25DOI: 10.1016/j.ijnonlinmec.2025.105195
Xin Lian , Haotian Wei , Weidong Zhang , Yuming Mao , Dongjie Jiang , Zhefeng Yu
This study introduces a semi-analytical method designed to efficiently and accurately analyze the nonlinear buckling response of complex curvilinear stiffened panel structures, addressing the computational challenges associated with such designs. The proposed method establishes displacement compatibility conditions to couple stiffeners and base plate, while employing Legendre polynomials to expand displacement fields, thereby enhancing robustness and accuracy. The Ritz method is utilized to solve the nonlinear buckling equations, yielding equilibrium path deviations consistently below 5 % compared to finite element method results while achieving a 61.43 % reduction in computation time. Parametric studies conducted under uniaxial and biaxial compressive loads confirm the capability of the method to accurately capture the nonlinear buckling behavior of curvilinear stiffened panels. The findings reveal a reduction in nonlinear critical loads, approximately 20 % lower than those predicted by linear buckling analysis, emphasizing the necessity of nonlinear analysis for accurate system evaluation. The study underscores the potential of the proposed semi-analytical method as a reliable and computationally efficient tool for nonlinear buckling analysis in complex stiffened structures.
{"title":"Nonlinear buckling analysis of helicoidal composite panels with curvilinear stiffeners","authors":"Xin Lian , Haotian Wei , Weidong Zhang , Yuming Mao , Dongjie Jiang , Zhefeng Yu","doi":"10.1016/j.ijnonlinmec.2025.105195","DOIUrl":"10.1016/j.ijnonlinmec.2025.105195","url":null,"abstract":"<div><div>This study introduces a semi-analytical method designed to efficiently and accurately analyze the nonlinear buckling response of complex curvilinear stiffened panel structures, addressing the computational challenges associated with such designs. The proposed method establishes displacement compatibility conditions to couple stiffeners and base plate, while employing Legendre polynomials to expand displacement fields, thereby enhancing robustness and accuracy. The Ritz method is utilized to solve the nonlinear buckling equations, yielding equilibrium path deviations consistently below 5 % compared to finite element method results while achieving a 61.43 % reduction in computation time. Parametric studies conducted under uniaxial and biaxial compressive loads confirm the capability of the method to accurately capture the nonlinear buckling behavior of curvilinear stiffened panels. The findings reveal a reduction in nonlinear critical loads, approximately 20 % lower than those predicted by linear buckling analysis, emphasizing the necessity of nonlinear analysis for accurate system evaluation. The study underscores the potential of the proposed semi-analytical method as a reliable and computationally efficient tool for nonlinear buckling analysis in complex stiffened structures.</div></div>","PeriodicalId":50303,"journal":{"name":"International Journal of Non-Linear Mechanics","volume":"178 ","pages":"Article 105195"},"PeriodicalIF":2.8,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144670708","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01Epub Date: 2025-06-26DOI: 10.1016/j.ijnonlinmec.2025.105190
Behrouz Karami , Mergen H. Ghayesh , Shahid Hussain
A geometrically imperfect third-order auxetic metamaterial thickness- and shear-deformable plate is considered, and both the non-linear bending as well as the free vibrations are analysed. Distribution of the effective material properties from plate’s top surface to the bottom one follows a functionally graded form; material properties are effectively approximated via genetic programming-assisted micromechanics models from previous studies. Without ignoring geometrical non-linearities, the fourfold coupled axial, transverse, rotational, and stretching non-linear motion equations are formulated for a geometrically imperfect third-order auxetic metamaterial thickness- and shear-deformable plate using Hamilton’s principle. The generalised differential quadrature method is implemented to discretise the motion equations; the discretised motion equations are then solved for both the non-linear bending as well as the linear free vibrations. For partial validation, the model is compared with available data from the open literature for simplified cases (i.e., single-layer homogeneous plates without metamaterial characteristics) and with a single-layered isotropic rectangular perfectly straight plate modelled in ANSYS. The complex non-linear mechanics and linear free vibration of the metamaterial system are analysed for different geometrical parameters, graphene origami contents, folding degrees, and geometrical imperfections, and also for both the symmetric and asymmetric distribution patterns of graphene origami. The results reveal that the geometric imperfections reduce the transverse deflection, and metamaterial plates with asymmetric graphene origami distributions consistently have the largest non-linear deflections among all the graphene origami distributions studied.
{"title":"Free vibration and large deformation characteristics of metamaterial thickness-deformable plates with initial geometrical imperfection","authors":"Behrouz Karami , Mergen H. Ghayesh , Shahid Hussain","doi":"10.1016/j.ijnonlinmec.2025.105190","DOIUrl":"10.1016/j.ijnonlinmec.2025.105190","url":null,"abstract":"<div><div>A geometrically imperfect third-order auxetic metamaterial thickness- and shear-deformable plate is considered, and both the non-linear bending as well as the free vibrations are analysed. Distribution of the effective material properties from plate’s top surface to the bottom one follows a functionally graded form; material properties are effectively approximated via genetic programming-assisted micromechanics models from previous studies. Without ignoring geometrical non-linearities, the fourfold coupled axial, transverse, rotational, and stretching non-linear motion equations are formulated for a geometrically imperfect third-order auxetic metamaterial thickness- and shear-deformable plate using Hamilton’s principle. The generalised differential quadrature method is implemented to discretise the motion equations; the discretised motion equations are then solved for both the non-linear bending as well as the linear free vibrations. For partial validation, the model is compared with available data from the open literature for simplified cases (i.e., single-layer homogeneous plates without metamaterial characteristics) and with a single-layered isotropic rectangular perfectly straight plate modelled in ANSYS. The complex non-linear mechanics and linear free vibration of the metamaterial system are analysed for different geometrical parameters, graphene origami contents, folding degrees, and geometrical imperfections, and also for both the symmetric and asymmetric distribution patterns of graphene origami. The results reveal that the geometric imperfections reduce the transverse deflection, and metamaterial plates with asymmetric graphene origami distributions consistently have the largest non-linear deflections among all the graphene origami distributions studied.</div></div>","PeriodicalId":50303,"journal":{"name":"International Journal of Non-Linear Mechanics","volume":"178 ","pages":"Article 105190"},"PeriodicalIF":2.8,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144513728","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01Epub Date: 2025-05-27DOI: 10.1016/j.ijnonlinmec.2025.105175
Yong Huang, Fei Peng
The coupled bending-torsion vibration model of the laminated coupling was established, taking into account nonlinear stiffness, mass eccentricity, and angular misalignment. First, a laminated coupling vibration test study was conducted. The results showed that the average relative error between the numerical model and the test results was 10.2 %. Subsequently, the effects of the misalignment amount and nonlinear stiffness on the vibration characteristics of the laminated coupling were analyzed. The results showed that an increase in the angular misalignment amount leads to an increase in the vibration amplitude of the laminated coupling. Additionally, nonlinear stiffness has a suppressive effect on the vibration amplitude of the system. Finally, the effects of the angular misalignment amount, bending/torsional stiffness critical values, and rotational speed on the vibration behavior of the laminated coupling were observed using bifurcation diagrams. The research results show that when the angular misalignment exceeds 2.3 × 10−3 rad, the critical value of bending stiffness is greater than 8.44 × 106 N/m, and the critical value of torsional stiffness is lower than 2.88 × 106 N·m/rad, the vibration amplitude of the laminated coupling tends to rise, and resonance may occur. Additionally, controlling the laminated coupling vibration amplitude is more effective when the rotational speed is either in the low-speed range or the high-speed range. The research results detailed in this paper not only inform the design of laminated coupling parameters but also provide guidance for the assembly process.
{"title":"Vibration behavior of laminated couplings based on angular misalignment and nonlinear stiffness characteristics","authors":"Yong Huang, Fei Peng","doi":"10.1016/j.ijnonlinmec.2025.105175","DOIUrl":"10.1016/j.ijnonlinmec.2025.105175","url":null,"abstract":"<div><div>The coupled bending-torsion vibration model of the laminated coupling was established, taking into account nonlinear stiffness, mass eccentricity, and angular misalignment. First, a laminated coupling vibration test study was conducted. The results showed that the average relative error between the numerical model and the test results was 10.2 %. Subsequently, the effects of the misalignment amount and nonlinear stiffness on the vibration characteristics of the laminated coupling were analyzed. The results showed that an increase in the angular misalignment amount leads to an increase in the vibration amplitude of the laminated coupling. Additionally, nonlinear stiffness has a suppressive effect on the vibration amplitude of the system. Finally, the effects of the angular misalignment amount, bending/torsional stiffness critical values, and rotational speed on the vibration behavior of the laminated coupling were observed using bifurcation diagrams. The research results show that when the angular misalignment exceeds 2.3 × 10<sup>−3</sup> rad, the critical value of bending stiffness is greater than 8.44 × 10<sup>6</sup> N/m, and the critical value of torsional stiffness is lower than 2.88 × 10<sup>6</sup> N·m/rad, the vibration amplitude of the laminated coupling tends to rise, and resonance may occur. Additionally, controlling the laminated coupling vibration amplitude is more effective when the rotational speed is either in the low-speed range or the high-speed range. The research results detailed in this paper not only inform the design of laminated coupling parameters but also provide guidance for the assembly process.</div></div>","PeriodicalId":50303,"journal":{"name":"International Journal of Non-Linear Mechanics","volume":"178 ","pages":"Article 105175"},"PeriodicalIF":2.8,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144665509","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01Epub Date: 2025-06-02DOI: 10.1016/j.ijnonlinmec.2025.105160
Elbens Carlos Viana Reis , Luis Paulo Silveira Machado , Surajit Sen
Monodispersed and inverse tapered granular chains with grain sizes varying uniformly from small to large under external harmonic excitations are numerically investigated. The control parameters are the number of granules, driving amplitude, driving frequency, and tapering parameter. The frequency response is analyzed using the transfer function, where properties of transmission, amplification, and filtering of signals are observed. For monodispersed chains, amplification peaks are described by functions of the control parameters. For sufficiently long monodispersed chains, signals at low frequencies () are amplified. Inverse tapered chains exhibit similar behavior with shorter chain lengths, as do monodispersed chains modeled with forces between granules with nonlinearity greater than that of the Hertzian contact law. Potential applications are in the fields of geosciences and oceanography, life sciences, military applications, and environmental monitoring.
{"title":"Infrasound amplification using simple strongly nonlinear granular metamaterials","authors":"Elbens Carlos Viana Reis , Luis Paulo Silveira Machado , Surajit Sen","doi":"10.1016/j.ijnonlinmec.2025.105160","DOIUrl":"10.1016/j.ijnonlinmec.2025.105160","url":null,"abstract":"<div><div>Monodispersed and inverse tapered granular chains with grain sizes varying uniformly from small to large under external harmonic excitations are numerically investigated. The control parameters are the number of granules, driving amplitude, driving frequency, and tapering parameter. The frequency response is analyzed using the transfer function, where properties of transmission, amplification, and filtering of signals are observed. For monodispersed chains, amplification peaks are described by functions of the control parameters. For sufficiently long monodispersed chains, signals at low frequencies (<span><math><mrow><mo>≈</mo><mtext>10</mtext><mspace></mspace><mtext>Hz</mtext></mrow></math></span>) are amplified. Inverse tapered chains exhibit similar behavior with shorter chain lengths, as do monodispersed chains modeled with forces between granules with nonlinearity greater than that of the Hertzian contact law. Potential applications are in the fields of geosciences and oceanography, life sciences, military applications, and environmental monitoring.</div></div>","PeriodicalId":50303,"journal":{"name":"International Journal of Non-Linear Mechanics","volume":"178 ","pages":"Article 105160"},"PeriodicalIF":2.8,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144204378","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper considers the computation of reduced-order models for systems of ordinary differential equations that include non-polynomial non-linearities. A targeted example is the case of a geometrically exact model of highly flexible slender structure, that includes, after space discretisation, trigonometric non-linear terms. With a suitable change of variables, this system can be rewritten in an equivalent one with polynomial non-linearities at most quadratic, at the price of introducing additional variables linked to algebraic equations, leading to a differential algebraic set of equations (DAE) to be solved. This DAE is reduced thanks to a normal form parametrisation of its invariant manifolds and selecting a set of master ones. Arbitrary order expansions are detailed for the coefficients of the change of variable and the reduced dynamics, using linear algebra in the space of multivariate polynomials of a given degree. In the case of a single non-linear mode reduction, a criterion to evaluate the quality of the normal form results is also proposed based on an estimation of the convergence radius of the polynomial asymptotic expansion representing truncated series. The method is then applied to compute a single mode reduction of three test cases – a Duffing oscillator, a simple pendulum and a clamped clamped beam with von Kármán model –, in order to investigate the effect of the algebraic part of the DAE on the quality of the model reduction and its validity range. Then, the more involved case of a cantilever beam modelled by geometrically exact finite elements is considered, underlining the ability of the method to produce accurate and converged results in a range of amplitude that can be bounded thanks to a convergence criterion.
{"title":"High order invariant manifold model reduction for systems with non-polynomial non-linearities: Geometrically exact finite element structures and validity limit","authors":"Aurélien Grolet , Alessandra Vizzaccaro , Marielle Debeurre , Olivier Thomas","doi":"10.1016/j.ijnonlinmec.2025.105138","DOIUrl":"10.1016/j.ijnonlinmec.2025.105138","url":null,"abstract":"<div><div>This paper considers the computation of reduced-order models for systems of ordinary differential equations that include non-polynomial non-linearities. A targeted example is the case of a geometrically exact model of highly flexible slender structure, that includes, after space discretisation, trigonometric non-linear terms. With a suitable change of variables, this system can be rewritten in an equivalent one with polynomial non-linearities at most quadratic, at the price of introducing additional variables linked to algebraic equations, leading to a differential algebraic set of equations (DAE) to be solved. This DAE is reduced thanks to a normal form parametrisation of its invariant manifolds and selecting a set of master ones. Arbitrary order expansions are detailed for the coefficients of the change of variable and the reduced dynamics, using linear algebra in the space of multivariate polynomials of a given degree. In the case of a single non-linear mode reduction, a criterion to evaluate the quality of the normal form results is also proposed based on an estimation of the convergence radius of the polynomial asymptotic expansion representing truncated series. The method is then applied to compute a single mode reduction of three test cases – a Duffing oscillator, a simple pendulum and a clamped clamped beam with von Kármán model –, in order to investigate the effect of the algebraic part of the DAE on the quality of the model reduction and its validity range. Then, the more involved case of a cantilever beam modelled by geometrically exact finite elements is considered, underlining the ability of the method to produce accurate and converged results in a range of amplitude that can be bounded thanks to a convergence criterion.</div></div>","PeriodicalId":50303,"journal":{"name":"International Journal of Non-Linear Mechanics","volume":"178 ","pages":"Article 105138"},"PeriodicalIF":2.8,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144204484","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01Epub Date: 2025-07-02DOI: 10.1016/j.ijnonlinmec.2025.105194
Suparno Bhattacharyya, Joseph P. Cusumano
We study the reduced order modeling of a piecewise-linear, globally nonlinear flexible oscillator in which a Bernoulli–Euler beam is subjected to a position-triggered kick force and a piecewise restoring force at its tip. The nonsmooth boundary conditions, which determine different regions of a hybrid phase space, can generally be expected to excite many degrees of freedom. With kick strength as parameter, the system’s bifurcation diagram is found to exhibit a range of periodic and chaotic behaviors. Proper orthogonal decomposition (POD) is used to obtain a single set of global basis functions spanning all of the hybrid regions. The reduced order model (ROM) dimension is chosen using previously developed energy closure analysis, ensuring approximate energy balance on the reduced subspace. This yields accurate ROMs with 8 degrees of freedom. Remarkably, we find that ROMs formulated using data from individual periodic steady states can nevertheless be used to reconstruct the entire bifurcation structure of the original system without updating. This demonstrates that, despite being constructed with steady state data, the ROMs model sufficiently small transients with enough accuracy to permit using simple continuation for the bifurcation diagram. We also find ROM subspaces obtained for different values of the bifurcation parameter are essentially identical. Thus, POD augmented with energy closure analysis is found to reliably yield effective dimension estimates and ROMs for this nonlinear, nonsmooth system that are robust across stability transitions, including even period doubling cascades to chaos, thereby greatly reducing data requirements and computational costs.
{"title":"Model reduction of a flexible nonsmooth oscillator recovers its entire bifurcation structure","authors":"Suparno Bhattacharyya, Joseph P. Cusumano","doi":"10.1016/j.ijnonlinmec.2025.105194","DOIUrl":"10.1016/j.ijnonlinmec.2025.105194","url":null,"abstract":"<div><div>We study the reduced order modeling of a piecewise-linear, globally nonlinear flexible oscillator in which a Bernoulli–Euler beam is subjected to a position-triggered kick force and a piecewise restoring force at its tip. The nonsmooth boundary conditions, which determine different regions of a hybrid phase space, can generally be expected to excite many degrees of freedom. With kick strength as parameter, the system’s bifurcation diagram is found to exhibit a range of periodic and chaotic behaviors. Proper orthogonal decomposition (POD) is used to obtain a single set of global basis functions spanning all of the hybrid regions. The reduced order model (ROM) dimension is chosen using previously developed energy closure analysis, ensuring approximate energy balance on the reduced subspace. This yields accurate ROMs with 8 degrees of freedom. Remarkably, we find that ROMs formulated using data from individual periodic steady states can nevertheless be used to reconstruct the entire bifurcation structure of the original system without updating. This demonstrates that, despite being constructed with steady state data, the ROMs model sufficiently small transients with enough accuracy to permit using simple continuation for the bifurcation diagram. We also find ROM subspaces obtained for different values of the bifurcation parameter are essentially identical. Thus, POD augmented with energy closure analysis is found to reliably yield effective dimension estimates and ROMs for this nonlinear, nonsmooth system that are robust across stability transitions, including even period doubling cascades to chaos, thereby greatly reducing data requirements and computational costs.</div></div>","PeriodicalId":50303,"journal":{"name":"International Journal of Non-Linear Mechanics","volume":"178 ","pages":"Article 105194"},"PeriodicalIF":2.8,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144557423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01Epub Date: 2025-05-09DOI: 10.1016/j.ijnonlinmec.2025.105150
Yunlong Zhao , Ruize Gao , Wangqun Deng , Mingming Shi , Li Huang , Wenkui Liu , Yongfeng Yang
This study analyzes the sensitivity of a double-disk rotor system to uncertain parameters and its nonlinear responses, while also conducting a propagation analysis for both single and multiple uncertain parameters. In this study, a dynamic model of a simply supported double-disk rotor system is developed using the finite element method. Additionally, the ellipsoidal convex set model is employed to quantify the uncertainty parameters in the rotor system. A Kriging surrogate model is developed to efficiently and accurately predict the nonlinear response of the rotor system under uncertainty. The global sensitivity of the rotor system's vibration response is analyzed using the Sobol global sensitivity index. Parameters with higher sensitivity indices are subsequently incorporated into the surrogate model to investigate the propagation mechanisms of both single and multiple uncertainty parameters of the rotor system. The results indicate that the critical speed of the rotor system is primarily influenced by the rotor density and elastic modulus. The vibration peaks of the rotor system are primarily influenced by the disk mass, viscous damping, and the degree of unevenness. Under the influence of multi-parameter uncertainty, the fluctuation ranges of the rotor system's peak vibration and critical speed are further extended.
{"title":"Uncertainty propagation analysis in a double-disk rotor system using a kriging surrogate model and ellipsoidal convex set boundaries","authors":"Yunlong Zhao , Ruize Gao , Wangqun Deng , Mingming Shi , Li Huang , Wenkui Liu , Yongfeng Yang","doi":"10.1016/j.ijnonlinmec.2025.105150","DOIUrl":"10.1016/j.ijnonlinmec.2025.105150","url":null,"abstract":"<div><div>This study analyzes the sensitivity of a double-disk rotor system to uncertain parameters and its nonlinear responses, while also conducting a propagation analysis for both single and multiple uncertain parameters. In this study, a dynamic model of a simply supported double-disk rotor system is developed using the finite element method. Additionally, the ellipsoidal convex set model is employed to quantify the uncertainty parameters in the rotor system. A Kriging surrogate model is developed to efficiently and accurately predict the nonlinear response of the rotor system under uncertainty. The global sensitivity of the rotor system's vibration response is analyzed using the Sobol global sensitivity index. Parameters with higher sensitivity indices are subsequently incorporated into the surrogate model to investigate the propagation mechanisms of both single and multiple uncertainty parameters of the rotor system. The results indicate that the critical speed of the rotor system is primarily influenced by the rotor density and elastic modulus. The vibration peaks of the rotor system are primarily influenced by the disk mass, viscous damping, and the degree of unevenness. Under the influence of multi-parameter uncertainty, the fluctuation ranges of the rotor system's peak vibration and critical speed are further extended.</div></div>","PeriodicalId":50303,"journal":{"name":"International Journal of Non-Linear Mechanics","volume":"178 ","pages":"Article 105150"},"PeriodicalIF":2.8,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144365490","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01Epub Date: 2025-06-25DOI: 10.1016/j.ijnonlinmec.2025.105196
B. Uspensky , K. Avramov , S. Malyshev , O. Nikonov
Cylindrical composite sandwich shell, which consists of two outer layers and thick honeycomb core, is considered. The outer thin layers are manufactured from composite orthotropic material and honeycomb core is manufactured from orthotropic plastic.
Parametric nonlinear oscillations of cylindrical shell under the action longitudinal time periodic force are considered. The honeycomb core is homogenized. As a result, orthotropic solid continuum is obtained. Stressed state of every layer is described by higher order shear theory, which uses five generalized displacements (three displacements projections and two rotations angles of normal to middle surfaces). The assumed-mode method is applied to obtain the system of nonlinear ordinary differential equations with respect to the generalized coordinates to describe the sandwich structure vibrations.
The shooting technique and continuation method are applied jointly to analyze the nonlinear oscillations, their stability and bifurcations. The geometrically nonlinear oscillations are considered in the principal parametric resonances with account of internal resonances. Stability and bifurcations of periodic motions are shown on the frequency response, which describes the structure nonlinear dynamics in principle parametric resonances.
{"title":"Geometrically nonlinear oscillations of composite sandwich cylindrical shell with honeycomb core under axial time periodic force","authors":"B. Uspensky , K. Avramov , S. Malyshev , O. Nikonov","doi":"10.1016/j.ijnonlinmec.2025.105196","DOIUrl":"10.1016/j.ijnonlinmec.2025.105196","url":null,"abstract":"<div><div>Cylindrical composite sandwich shell, which consists of two outer layers and thick honeycomb core, is considered. The outer thin layers are manufactured from composite orthotropic material and honeycomb core is manufactured from orthotropic plastic.</div><div>Parametric nonlinear oscillations of cylindrical shell under the action longitudinal time periodic force are considered. The honeycomb core is homogenized. As a result, orthotropic solid continuum is obtained. Stressed state of every layer is described by higher order shear theory, which uses five generalized displacements (three displacements projections and two rotations angles of normal to middle surfaces). The assumed-mode method is applied to obtain the system of nonlinear ordinary differential equations with respect to the generalized coordinates to describe the sandwich structure vibrations.</div><div>The shooting technique and continuation method are applied jointly to analyze the nonlinear oscillations, their stability and bifurcations. The geometrically nonlinear oscillations are considered in the principal parametric resonances with account of internal resonances. Stability and bifurcations of periodic motions are shown on the frequency response, which describes the structure nonlinear dynamics in principle parametric resonances.</div></div>","PeriodicalId":50303,"journal":{"name":"International Journal of Non-Linear Mechanics","volume":"178 ","pages":"Article 105196"},"PeriodicalIF":2.8,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144511063","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}