Meccanica最新文献_第3页

Belief reliability of structures with hybrid uncertainties 具有混合不确定性的结构的信念可靠性

IF 1.9 3区工程技术

Meccanica Pub Date : 2024-08-02 DOI: 10.1007/s11012-024-01832-z

Sushma H. Metagudda, A. S. Balu

{"title":"Belief reliability of structures with hybrid uncertainties","authors":"Sushma H. Metagudda, A. S. Balu","doi":"10.1007/s11012-024-01832-z","DOIUrl":"10.1007/s11012-024-01832-z","url":null,"abstract":"<div>Reliability of structures is evaluated by considering uncertainties present in the system, which can be characterized into aleatory and epistemic. Inherent randomness in the physical environment leads to aleatory, whereas insufficient knowledge about the system leads to epistemic uncertainty. For the reliability evaluation, ascertaining the sources of uncertainties poses a great challenge since both uncertainties coexist widely in structural systems. Aleatory uncertainties are quantified by probabilistic measures (such as first order reliability method, second order reliability method and Monte Carlo techniques), whereas epistemic uncertainties are quantified by various non-probabilistic approaches (such as interval analysis methods, evidence theory, possibility theory and fuzzy theory). However, major issues like interval extension problem and duality conditions that lead to overestimation hinder the versatility of application of such methods, thus uncertainty theory has been emerged to overcome these limitations. Given the existing uncertainties and limitations, a hybrid strategy has been constructed and referred to as “belief reliability”. A belief reliability metric is integration of three key factors: design margin, aleatory and epistemic uncertainty factor to evaluate the reliability of the structural system. In this paper, Monte Carlo simulation is adopted to account for aleatory uncertainty. On the other hand, epistemic uncertainty is quantified through adjustment factor approach using FMEA (failure mode effective analysis). Numerical examples are presented to substantiate the proposed methodology being applied to variety of problems both implicit and explicit nature in structural engineering.</div>","PeriodicalId":695,"journal":{"name":"Meccanica","volume":"59 9","pages":"1593 - 1606"},"PeriodicalIF":1.9,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141882401","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}

引用次数: 0

A thermodynamical suspension model for blood 血液热力学悬浮模型

IF 2.7 3区工程技术

Meccanica Pub Date : 2024-08-02 DOI: 10.1007/s11012-024-01859-2

Matteo Gorgone, Carmelo Filippo Munafò, Annunziata Palumbo, Patrizia Rogolino

引用次数: 0

A method to enhance the nonlinear magnetic plucking for vibration energy harvesters 增强振动能量收集器非线性磁拨的方法

IF 1.9 3区工程技术

Meccanica Pub Date : 2024-08-02 DOI: 10.1007/s11012-024-01856-5

Michele Rosso, Simone Cuccurullo, Filippo Pietro Perli, Federico Maspero, Alberto Corigliano, Raffaele Ardito

引用次数: 0

A new combined fabrication process to shape small flexure hinges 塑造小型挠性铰链的新型组合制造工艺

IF 1.9 3区工程技术

Meccanica Pub Date : 2024-07-27 DOI: 10.1007/s11012-024-01860-9

Marco Fava, Vincenzo Parenti-Castelli, Michele Conconi, Nicola Sancisi

引用次数: 0

Influence of extruder geometry and bio-ink type in extrusion-based bioprinting via an in silico design tool 通过硅学设计工具研究挤压机几何形状和生物墨水类型对挤压式生物打印的影响

IF 1.9 3区工程技术

Meccanica Pub Date : 2024-07-25 DOI: 10.1007/s11012-024-01862-7

Francesco Chirianni, Giuseppe Vairo, Michele Marino

{"title":"Influence of extruder geometry and bio-ink type in extrusion-based bioprinting via an in silico design tool","authors":"Francesco Chirianni, Giuseppe Vairo, Michele Marino","doi":"10.1007/s11012-024-01862-7","DOIUrl":"10.1007/s11012-024-01862-7","url":null,"abstract":"<div>Planning a smooth-running and effective extrusion-based bioprinting process is a challenging endeavor due to the intricate interplay among process variables (e.g., printing pressure, nozzle diameter, extrusion velocity, and mass flow rate). A priori predicting how process variables relate each other is complex due to both the non-Newtonian response of bio-inks and the extruder geometries. In addition, ensuring high cell viability is of paramount importance, as bioprinting procedures expose cells to stresses that can potentially induce mechanobiological damage. Currently, in laboratory settings, bioprinting planning is often conducted through expensive and time-consuming trial-and-error procedures. In this context, an in silico strategy has been recently proposed by the authors for a clear and streamlined pathway towards bioprinting process planning (Chirianni et al. in Comput Methods Appl Mech Eng 419:116685, 2024. https://doi.org/10.1016/j.cma.2023.116685). The aim of this work is to investigate on the influence of bio-ink polymer type and of cartridge-nozzle connection shape on the setting of key process variables by adopting such in silico strategy. In detail, combinations of two different bio-inks and three different extruder geometries are considered. Nomograms are built as graphical fast design tools, thus informing how the printing pressure, the mass flow rate and the cell viability vary with extrusion velocity and nozzle diameter.</div>","PeriodicalId":695,"journal":{"name":"Meccanica","volume":"59 8","pages":"1285 - 1299"},"PeriodicalIF":1.9,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11012-024-01862-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141775374","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}

引用次数: 0

Multimodal uncertainty propagation analysis for the morphing wings of cross-domain variant aircraft 跨域变体飞机变形机翼的多模式不确定性传播分析

IF 1.9 3区工程技术

Meccanica Pub Date : 2024-07-22 DOI: 10.1007/s11012-024-01857-4

Qishui Yao, Siyuan Liu, Jiachang Tang, Hairui Zhang, Zitong Qiu

{"title":"Multimodal uncertainty propagation analysis for the morphing wings of cross-domain variant aircraft","authors":"Qishui Yao, Siyuan Liu, Jiachang Tang, Hairui Zhang, Zitong Qiu","doi":"10.1007/s11012-024-01857-4","DOIUrl":"10.1007/s11012-024-01857-4","url":null,"abstract":"<div>A multimodal distribution based uncertainty analysis method for cross-domain aircraft morphing wing mechanisms is proposed to address the engineering issue of the reliability of morphing mechanisms. This method is based on Gaussian mixture model, isotropic sparse mesh method combined with maximum entropy method analysis. In the working environment of the morphing wings, the external load exhibits a multimodal distribution with changes in flight altitude and geographical location. Traditional uncertainty methods are difficult to accurately determine the reliability of aircraft under the influence of multiple variable influencing factors. Therefore, the proposed method is proposed to evaluate the reliability of morphing wing mechanisms. Firstly, a Gaussian mixture model is used to establish the mixture density function of the pressure and the leading edge size of the variant aircraft. Secondly, the integral points and weights of the multimodal random variables are calculated by the sparse grid method. Finally, an adaptive convergence mechanism is used to improve the uncertainty propagation accuracy. After a mathematical example and two engineering examples, it can be considered that the proposed method has a certain reference value in analyzing the uncertainty propagation under the multimodal distribution state of multiple factors.</div>","PeriodicalId":695,"journal":{"name":"Meccanica","volume":"59 9","pages":"1555 - 1576"},"PeriodicalIF":1.9,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141737776","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}

引用次数: 0

Instability of double-diffusive natural convection in a vertical Brinkman porous layer 垂直布林克曼多孔层中双扩散自然对流的不稳定性

IF 1.9 3区工程技术

Meccanica Pub Date : 2024-07-22 DOI: 10.1007/s11012-024-01851-w

Shuting Lu, Beinan Jia, Jialu Wang, Yongjun Jian

{"title":"Instability of double-diffusive natural convection in a vertical Brinkman porous layer","authors":"Shuting Lu, Beinan Jia, Jialu Wang, Yongjun Jian","doi":"10.1007/s11012-024-01851-w","DOIUrl":"10.1007/s11012-024-01851-w","url":null,"abstract":"<div>The extended Brinkman model is employed in this study to investigate the instability of double diffusion natural convection in porous layers caused by vertical variations in boundary temperature and solute concentration. The stability of fluid flow is determined by discussing the temporal evolution of normal mode disturbances superposed onto the fundamental state. The linear dynamics problem is formulated as an Orr–Sommerfeld eigenvalue problem and solved numerically using the Chebyshev collocation method. The effects of thermal/solute Darcy–Rayleigh number (RaT/RaS), Lewis number (Le), and Darcy–Prandtl number (PrD) on system instability are analyzed. Growth rate curves indicate that solute Darcy–Rayleigh numbers can induce flow instability. Neutral stability curves show that increasing RaT/RaS promotes instability. There is a critical threshold for Le, exceeding this amplifies instability, while falling below suppresses it. For large RaT values, varying PrD leads to different effects of increasing RaS on flow stability. The stability of the system is significantly dependent on RaT and RaS, with the critical value of the Le playing a decisive role in system stability. Additionally, PrD significantly affects system instability under certain conditions.</div>","PeriodicalId":695,"journal":{"name":"Meccanica","volume":"59 9","pages":"1539 - 1553"},"PeriodicalIF":1.9,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141737777","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}

引用次数: 0

Computational modeling of cell motility and clusters formation in enzyme-sensitive hydrogels 酶敏感水凝胶中细胞运动和团块形成的计算建模

IF 1.9 3区工程技术

Meccanica Pub Date : 2024-07-22 DOI: 10.1007/s11012-024-01843-w

Pierfrancesco Gaziano, Michele Marino

{"title":"Computational modeling of cell motility and clusters formation in enzyme-sensitive hydrogels","authors":"Pierfrancesco Gaziano, Michele Marino","doi":"10.1007/s11012-024-01843-w","DOIUrl":"10.1007/s11012-024-01843-w","url":null,"abstract":"<div>In this paper, we propose an extension of a previous model of cell motility in tissue engineering applications recently developed by the authors. Achieving large-scale production of neo-tissue through biofabrication technologies remains challenging owing to the need of thoroughly optimizing all the relevant process variables, a task hardly attainable through solely trial and error approaches. Therefore, the present work is intended to provide a valid and effective computational-based support for neo-tissue formation, with a specific focus on the preliminary phase of such process, in which cells move through a polymeric scaffold (hydrogel) and then compact into clusters. Cell motility is modeled by resorting to the phase-field method, and by incorporating diffusion of nutrients from the external culture bath as well as the expression by cells of chemoattractant substances that bias the random path they otherwise would follow. The previous model has been enriched by additionally encompassing the secretion of enzymes by cells that cleave the crosslinks between the hydrogel polymer chains. As such, in the present model hydrogel degradation exhibits spatio-temporal variations in its chemo-physical properties related to the local amount of enzymes, which deeply affects cell motility. Numerical results showcase the pivotal importance of the cells micro-environment properties for their crawling in hydrogel scaffolds, opening towards the development of a predictive computational-aided optimization tool for neo-tissue growth in bioprinted scaffolds.</div>","PeriodicalId":695,"journal":{"name":"Meccanica","volume":"59 8","pages":"1335 - 1349"},"PeriodicalIF":1.9,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11012-024-01843-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141775375","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}

引用次数: 0

Using a robust mu-synthesis based controller to eliminate the adverse effects of uncertainties and external disturbances in nonlinear 3D overhead cranes with hoisting mechanism 使用基于鲁棒缪合成的控制器消除带起升机构的非线性 3D 桥式起重机中的不确定性和外部干扰的不利影响

IF 1.9 3区工程技术

Meccanica Pub Date : 2024-07-21 DOI: 10.1007/s11012-024-01846-7

Mohammad Khoshnazar, Amir Hossein Barjini, Hamed Moradi

{"title":"Using a robust mu-synthesis based controller to eliminate the adverse effects of uncertainties and external disturbances in nonlinear 3D overhead cranes with hoisting mechanism","authors":"Mohammad Khoshnazar, Amir Hossein Barjini, Hamed Moradi","doi":"10.1007/s11012-024-01846-7","DOIUrl":"10.1007/s11012-024-01846-7","url":null,"abstract":"<div>In this paper, a robust (mu)-optimal controller is developed for a three-dimensional overhead crane system with hoisting mechanism using the (mu)-synthesis method. The 3D overhead crane system is modeled as an underactuated five degrees of freedom (5DOFs) system with uncertain parameters. The system receives only three input signals: Two forces that move the trolley along the (x) and (y) axes, and the hoisting force that moves the payload along the rope. In the first step to design the (mu)-optimal controller for the 3D overhead crane system, nonlinear equations of the system are linearized around the equilibrium point to obtain the transfer functions. Next, to ensure that the system performs well and is robust against uncertainties, efficient weight functions for both performance and uncertainty are calculated. Finally, the (mu)-optimal robust controller is designed using MATLAB’s Robust Control Toolbox, implementing the D-K iteration algorithm, and analyzing (mu)-plots. It is shown that not only does the proposed controller provide nominal stability and performance, but it also ensures robust stability and performance. The proposed controller is applied to the original nonlinear system and simulation results demonstrate that this controller satisfies the control objectives well and is also robust to severe parametric uncertainties and external disturbances. Moreover, this controller provides better results compared to a conventional sliding mode controller (SMC) and a second-order SMC, by applying much less control forces. Another advantage of the proposed controller is that, unlike the other two controllers, it does not need feedback from states at the speed level. Therefore, in practice, the proposed robust controller needs fewer and cheaper sensors.</div>","PeriodicalId":695,"journal":{"name":"Meccanica","volume":"59 9","pages":"1517 - 1538"},"PeriodicalIF":1.9,"publicationDate":"2024-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141737778","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}

引用次数: 0

Analysis of vibrational characteristics of all-composite honeycomb core sandwich panels: theoretical and experimental study 全复合蜂窝芯夹芯板振动特性分析：理论与实验研究

IF 1.9 3区工程技术

Meccanica Pub Date : 2024-07-19 DOI: 10.1007/s11012-024-01855-6

Chu Chen, Xu Zhuo, Li Hui, Xu Pei-yao, Sun Xian-chao, Gu Da-wei, Hu Chang-cheng, Li He, Wen Bang-chun

引用次数: 0