Meccanica最新文献

{"title":"A novel rapid positioning method for dynamic load location based on Newmark explicit method and modal shape comparison method","authors":"Zhengshu Wang,&nbsp;Jinhui Jiang","doi":"10.1007/s11012-025-01955-x","DOIUrl":"10.1007/s11012-025-01955-x","url":null,"abstract":"<div><p>Accurately determining the location and magnitude of loads acting on a structure is crucial for structural design, optimization, and health monitoring. However, identifying the source of vibration through direct measurement is extremely challenging. Therefore, developing a rapid and accurate method for dynamic load location identification is essential. This paper focuses on proportionally damped continuous systems and proposes a novel and efficient method for dynamic load location identification. The traditional \"response-system-load\" framework for dynamic load identification is transformed into a \"response-modal response-system-modal load\" framework based on the Newmark explicit method, determining the modal loads of various orders in the vibration system. The modal shapes corresponding to the load location are then determined using the least squares inverse method, and the load location is identified by calculating the mode shape deviation function. Subsequently, an iterative strategy for dynamic load location identification is proposed to further enhance the computational efficiency of the method on complex structures. Simulated results demonstrate that, compared to the virtual load method, this method does not require load identification for every possible point, but only needs to identify modal loads once, significantly improving the speed of dynamic load location identification. Furthermore, the algorithm demonstrates high precision and excellent noise resistance in the identification of sinusoidal loads, broadband random loads, and impact loads. It also demonstrates robust adaptability under conditions of model uncertainties. To further verify the performance of the algorithm in practical applications, experimental studies on dynamic load identification were conducted on a simply supported beam system, and the results show that the algorithm is effective.</p></div>","PeriodicalId":695,"journal":{"name":"Meccanica","volume":"60 4","pages":"841 - 859"},"PeriodicalIF":1.9,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143896757","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}

{"title":"Optimized input shaping for multi-mode hanging chains using a modal model approach","authors":"Faisal Alobaid,&nbsp;Khalid Alghanim","doi":"10.1007/s11012-024-01898-9","DOIUrl":"10.1007/s11012-024-01898-9","url":null,"abstract":"<div><p>This work presents a study on the dynamics and control of a hanging chain suspended from an overhead crane, using modal analysis and input shaping techniques. Two standard input shaping functions, step, and polynomial, are evaluated alongside a piecewise cosine function. The effectiveness of proposed input shaping techniques is evaluated based on their impact on the hanging chain’s various mode shapes contribution. The study introduces a key innovation in solving input coefficients for flexible structures by utilizing the modal model matrix created from the Finite Difference Method in conjunction with Laplace transformations. This approach aims to achieve various solutions for the input functions depending on the number of modes considered in the system. The solution varies depending on the number of modes contributing in the response. This allows for highly precise control and provides insights into their potential applications in dynamic control systems involving flexible structures.</p></div>","PeriodicalId":695,"journal":{"name":"Meccanica","volume":"60 4","pages":"825 - 840"},"PeriodicalIF":1.9,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143896693","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}

{"title":"Numerical investigation on the effects of stacking pattern and thickness ratio on the ballistic performance of tortoiseshell-like glass composite","authors":"Jun Sun,&nbsp;Xin Zhang,&nbsp;Chunxu Zhao,&nbsp;Jun Li,&nbsp;Hai Mei,&nbsp;Xiang Liu,&nbsp;Shilin Yan","doi":"10.1007/s11012-025-01953-z","DOIUrl":"10.1007/s11012-025-01953-z","url":null,"abstract":"<div><p>Transparent protective composites inspired by natural tortoiseshell structures offer a promising solution for high-performance ballistic applications. However, the design optimization of these composites under dynamic impact conditions remains underexplored. This study systematically examines the effects of various stacking patterns, layer thickness ratios, and unit block side lengths on the ballistic performance of tortoiseshell-like glass composites. The results indicate that eccentric staggered configurations significantly outperform aligned and centered configurations due to enhanced stress wave attenuation at complex interfaces. Equal thickness ratios (1:1) optimize energy dissipation by balancing interfacial crack propagation and unit block damage, while unequal ratios degrade performance by concentrating stress in thinner layers. Notably, variations in unit block size have minimal impact on overall impact resistance, as increased interface length compensates for reduced interface density. These findings advance the development of bioinspired protective materials for military, aerospace, and civil safety applications, offering a pathway to mitigate trade-offs between structural weight and ballistic resilience.</p></div>","PeriodicalId":695,"journal":{"name":"Meccanica","volume":"60 4","pages":"809 - 824"},"PeriodicalIF":1.9,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143896692","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}

{"title":"Maximum entropy principle handled by using complex fractional moments","authors":"Lizhi Niu,&nbsp;Mario Di Paola,&nbsp;Antonina Pirrotta,&nbsp;Wei Xu","doi":"10.1007/s11012-025-01949-9","DOIUrl":"10.1007/s11012-025-01949-9","url":null,"abstract":"<div><p>A novel Maximum Entropy Principle method constrained by Complex Fractional Moments is proposed in this paper, which can be applied for reconstructing of approximate probability distribution equations with few complex fractional moments. By introducing complex fractional moments with different imaginary parameters into the entropy functional, an extended entropy functional with unknown Lagrange multipliers is constructed, which is utilized for deriving the approximate probability density function. The new method is extended to obtaining probability density function in stochastic dynamic systems based on the complex fractional moment equations which is derived from Fokker–Planck-Kolmogorov equation. Numerical simulations verified the effectiveness of the approach.</p></div>","PeriodicalId":695,"journal":{"name":"Meccanica","volume":"60 8","pages":"2607 - 2620"},"PeriodicalIF":2.1,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145230256","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}

{"title":"Development and kinematic analysis of origami-inspired retractable roof structures","authors":"Jinyu Lu,&nbsp;Jiang-Jun Hou,&nbsp;Ding Lu,&nbsp;Haichen Zhang","doi":"10.1007/s11012-025-01951-1","DOIUrl":"10.1007/s11012-025-01951-1","url":null,"abstract":"<div><p>The application of retractable roof structures has enhanced the urban landscape, particularly in large-scale public buildings. Miura-ori is an immensely popular and highly inspiring method of paper folding. In this paper, three novel design families of retractable roof structures, integrating Miura-ori (and its variations) with scissor hinge units, are proposed. A concise overview of the concepts of Miura-ori (including its arched and fan-shaped variations), scissor joint unit, and rigid panel is first provided. Subsequently, coordinated motion conditions for the three proposed retractable roof structures are elaborately derived using geometric formulas, and the corresponding solutions are provided when the coordinated motion is not feasible. Lastly, after parameterizing the rigid-panel model, the motion mechanism of the retractable roof structures is analyzed exhaustively. The results indicate that all three new structures can achieve smooth opening and closing operations without motion interference. The proposed novel retractable roof structures enrich the variety of architectural structures and provide practical guidance for engineering applications.</p></div>","PeriodicalId":695,"journal":{"name":"Meccanica","volume":"60 4","pages":"785 - 808"},"PeriodicalIF":1.9,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143896691","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}

{"title":"Shock physics in compressible thermoelastic and thermoviscoelastic solids","authors":"K. S. Surana,&nbsp;E. Abboud","doi":"10.1007/s11012-024-01893-0","DOIUrl":"10.1007/s11012-024-01893-0","url":null,"abstract":"<div><p>In this paper, we present mathematical models, methods of obtaining their solutions, and the model problem studies for wave propagation in compressible thermoelastic (TE) and thermoviscoelastic (TVE) solid media, i.e., this research addresses shock physics in compressible TVES without memory. The mathematical model consists of conservation and balance laws (CBL) of classical continuum mechanics (CCM) derived using the contravariant second Piola–Kirchhoff stress tensor and the convected time derivative of the covariant Green’s strain tensor up to order <i>n</i>. Constitutive theories are derived using conjugate pairs in the entropy inequality augmented with strain rates up to order <i>n</i> and the representation theorem. The dissipation mechanism in this theory is due to ordered rates of Green’s strain tensor up to order <i>n</i>. This mathematical model permits finite deformation, finite strain, as well as finite strain rate deformation physics and is thermodynamically and mathematically consistent. The solutions of the initial value problem (<i>IVP</i>) described by this mathematical model are obtained using a space-time coupled variationally consistent space-time finite element method based on the space-time residual functional for a space-time strip with time marching. The p-version hierarchical space-time local approximations of higher degree as well as higher-order global differentiability are considered in higher-order scalar product spaces. This permits accurate computations of a posteriori errors in the solution measured in the <span>(L_2)</span> norm of the space-time residual functional and provides means of improving the accuracy of computed solutions. In the research presented in this paper, no assumptions or approximations are made regarding shock wave, shock structure, or its analytic (or non-analytic) nature. This work relies on the mathematical models and the computational infrastructure presented in this paper to reveal and simulate shock physics details: deviatoric stress wave, density wave, their propagations, reflections, and interactions in compressible TVES medium without rheology. Detailed model problem studies are presented to illustrate all aspects of the shock physics. To our knowledge, this work is not available in the published literature. This paper is the first presentation of this research.</p></div>","PeriodicalId":695,"journal":{"name":"Meccanica","volume":"60 4","pages":"755 - 783"},"PeriodicalIF":1.9,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11012-024-01893-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143896690","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improving the evaluation of static bifurcations in locally damaged parabolic arches","authors":"U. Eroğlu,&nbsp;G. Ruta,&nbsp;E. Tüfekci,&nbsp;A. Paolone","doi":"10.1007/s11012-024-01932-w","DOIUrl":"10.1007/s11012-024-01932-w","url":null,"abstract":"<div><p>Even local small cracks may induce instability and failure or operativity loss before the crisis for the intact material is actually attained. Thus, damage models and the possibility of their identification have become trendy subjects in structural mechanics. We previously studied buckling and post-buckling of parabolic arches with a local transverse small crack by two perturbations of the finite field equations and boundary conditions. One perturbation describes non-trivial fundamental paths adjacent to the undamaged initial shape, the second describes the germ of a bifurcated path in the vicinity of a critical point. We think the arch consisiting of two undamaged parts, connected by lumped elasticities quantified by notions of linear fracture mechanics, at the cracked cross-section. In this paper we highlight that in a previous investigation of ours on the same subject some physically meaningful terms were wrong in the perturbed equations. This implies that the values of the incremental external load considered in the applications of that investigation need to be amended. Thus, here we present perturbed equations that are complete and, by the same procedure, we find more reliable numerical results for the critical loads and a more refined description of the germ of the post-buckling path, besides providing clear physical interpretation for seemingly paradoxical results.</p></div>","PeriodicalId":695,"journal":{"name":"Meccanica","volume":"60 4","pages":"739 - 754"},"PeriodicalIF":1.9,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11012-024-01932-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143896659","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A method for designing digital hydraulic pumps with variable angular speed","authors":"Dimitri Oliveira e Silva,&nbsp;Marcos Paulo Nostrani,&nbsp;Gierri Waltrich,&nbsp;Victor Juliano De Negri","doi":"10.1007/s11012-025-01946-y","DOIUrl":"10.1007/s11012-025-01946-y","url":null,"abstract":"<div><p>Recent researches on digital hydraulics have shown the potential of this technology for designing hydraulic systems with improved energy efficiency compared to conventional hydraulic systems. While most studies have concentrated on proposing novel architectures for digital hydraulic systems and assessing their performance in specific applications, the development of comprehensive guidelines for component sizing and system configuration remains an important task as the technology advances. In this context, this paper presents an approach for designing Variable Speed Digital Hydraulic Pumps that addresses key challenges in determining the optimal number of pump units and selecting the most suitable combinations according to the operating points. By employing an optimization algorithm, the proposed method configures different digital hydraulic pumps designs by defining the number of pump units and allocating volumetric displacements based on pre-defined numerical patterns. These digital hydraulic pumps are then evaluated to identify the pump design that best meets the system requirements. Experimental results demonstrate that the method effectively identifies the optimal combination of pump units, prioritizing overall efficiency. Consequently, the proposed approach provides a significant contribution to the design of digital hydraulic pumps powered by variable-speed electric motors. Furthermore, the method is versatile, as it is independent of the pump units’ construction principles and the type of electrical prime mover, ensuring broad applicability.</p></div>","PeriodicalId":695,"journal":{"name":"Meccanica","volume":"60 4","pages":"723 - 737"},"PeriodicalIF":1.9,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143896794","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}

{"title":"Impact of mechanical properties of aneurysms and intraluminal thrombus on abdominal aortic aneurysm outcomes","authors":"Gaia Caruso,&nbsp;Miguel Ángel Martínez,&nbsp;Estefanía Peña","doi":"10.1007/s11012-025-01950-2","DOIUrl":"10.1007/s11012-025-01950-2","url":null,"abstract":"<div><p>This study aims to examine how changes in material coefficients impact the mechanical responses of AAA models, including both cases with and without the ILT. The main focus will be on identifying the material coefficients that most significantly influence strain and stress fields, using the GHO model, which is widely regarded as the most popular hyperelastic model. The findings of this study reveal that compliant AAAs are particularly sensitive to fiber dispersion, which exerts a substantial influence on stress distribution and deformation patterns. In stiffer AAAs, however, matrix stiffness emerges as the key player. Notably, the study of interactions among all GHO parameters demonstrate that even minor adjustments can dramatically shift model behavior, emphasizing the importance of finely fitted parameter combinations for accurate predictions. The impact of ILT material properties on AAA mechanical behavior was found to be relatively minor, indicating that precise fitting of ILT coefficients may not be essential. However, the inclusion of the ILT itself was important, as it played a crucial role in shielding the AAA wall by reducing stress. This study offers valuable insights into the material modeling of AAA tissue and the significance of the ILT. The findings can be instrumental in optimizing patient-specific computational models, enhancing the accuracy of AAA wall material behavior, while also incorporating the ILT’s effects.</p></div>","PeriodicalId":695,"journal":{"name":"Meccanica","volume":"60 8","pages":"2271 - 2290"},"PeriodicalIF":2.1,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11012-025-01950-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145230474","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spatial mapping tooth profile design and transmission characteristics analysis of harmonic drive based on scaling factor","authors":"Ke Xiao,&nbsp;Feifei Yuan,&nbsp;Jianlin Wang,&nbsp;Linjun Li,&nbsp;Yanfeng Han,&nbsp;Cheng Wang,&nbsp;Xiujie Chen","doi":"10.1007/s11012-024-01933-9","DOIUrl":"10.1007/s11012-024-01933-9","url":null,"abstract":"<div><p>This study proposes a method for the design of spatial mapping profile for harmonic drives based on scaling factors, and provides an in-depth analysis of their transmission characteristics. Firstly, the tooth profile mapping equations for harmonic drive are established by using the rack approximation method and the fundamental theorem of meshing. Then, scaling factors are introduced, and planar profiles of harmonic drives with varying scaling factors are derived through the application of conjugate theory. This study investigates the effect of scaling factors on the conjugate interval. Especially, loss areas for the quadratic conjugation and two-point conjugation are analyzed. The loss areas for the quadratic conjugation and two-point conjugation increase as the scaling factor increases. According to the nonlinear deformation of the FS teeth in the axial direction, a spatial mapping profile of the harmonic drive is developed, and a finite element method is employed to analyze the Von-Mises stress and contact stress of the HD. A reasonable scaling factor is beneficial to increase the meshing interval and improve the stress distribution of the assembly stress, tooth root bending stress, and tooth surface contact stress of the harmonic drive.</p></div>","PeriodicalId":695,"journal":{"name":"Meccanica","volume":"60 2","pages":"475 - 495"},"PeriodicalIF":1.9,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11012-024-01933-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143533191","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}