Moustafa S. Taima , Tamer A. El-Sayed , Michael I. Friswell
{"title":"二维功能梯度材料锥形旋转梁的动力稳定性分析:Floquet理论方法的比较研究","authors":"Moustafa S. Taima , Tamer A. El-Sayed , Michael I. Friswell","doi":"10.1016/j.tws.2025.113257","DOIUrl":null,"url":null,"abstract":"<div><div>This study investigates the dynamic and stability characteristics of rotating beams made from two-dimensional functionally graded materials (2D FGMs) with tapered geometry. Dynamics refers to the beam’s inherent vibrational behavior determined by its natural frequencies and/or time responses, and stability examines whether the system’s response remains bounded (stable) or becomes unbounded (unstable) under periodic excitation. The material properties are defined using a power law distribution model. The stiffness and mass matrices are derived based on the principle of virtual energy and evaluated using Bernoulli–Euler beam theories. Unlike previous studies, which often focus on single approaches, this research employs Floquet theory with three distinct techniques to evaluate the state transition matrix (STM), offering a comprehensive comparative analysis. The techniques investigated are the first-order step approximation, the improved integration method, and the second-order step approximation. The comparison identifies the most efficient approach in terms of accuracy and computational time, addressing limitations of existing methods. The impact of mean rotating speed, hub radius, dynamic amplitude factor, functionally graded (FG) material indexes, and taper ratio on the stability characteristics of the rotating 2D FGMs tapered beam is thoroughly analyzed. The results provide valuable insights into the dynamic behavior and stability of such beams, guiding the design and optimization of advanced rotating beam structures. The results indicate that the second-order approximation for computing the transition matrix achieves higher accuracy in predicting the instability boundaries compared to the first-order approximation, while being less time consuming than the improved integration method.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":"213 ","pages":"Article 113257"},"PeriodicalIF":5.7000,"publicationDate":"2025-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Dynamic stability analysis of tapered rotating beams with 2D functionally graded materials: A comparative study of Floquet theory approaches\",\"authors\":\"Moustafa S. Taima , Tamer A. El-Sayed , Michael I. Friswell\",\"doi\":\"10.1016/j.tws.2025.113257\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>This study investigates the dynamic and stability characteristics of rotating beams made from two-dimensional functionally graded materials (2D FGMs) with tapered geometry. Dynamics refers to the beam’s inherent vibrational behavior determined by its natural frequencies and/or time responses, and stability examines whether the system’s response remains bounded (stable) or becomes unbounded (unstable) under periodic excitation. The material properties are defined using a power law distribution model. The stiffness and mass matrices are derived based on the principle of virtual energy and evaluated using Bernoulli–Euler beam theories. Unlike previous studies, which often focus on single approaches, this research employs Floquet theory with three distinct techniques to evaluate the state transition matrix (STM), offering a comprehensive comparative analysis. The techniques investigated are the first-order step approximation, the improved integration method, and the second-order step approximation. The comparison identifies the most efficient approach in terms of accuracy and computational time, addressing limitations of existing methods. The impact of mean rotating speed, hub radius, dynamic amplitude factor, functionally graded (FG) material indexes, and taper ratio on the stability characteristics of the rotating 2D FGMs tapered beam is thoroughly analyzed. The results provide valuable insights into the dynamic behavior and stability of such beams, guiding the design and optimization of advanced rotating beam structures. The results indicate that the second-order approximation for computing the transition matrix achieves higher accuracy in predicting the instability boundaries compared to the first-order approximation, while being less time consuming than the improved integration method.</div></div>\",\"PeriodicalId\":49435,\"journal\":{\"name\":\"Thin-Walled Structures\",\"volume\":\"213 \",\"pages\":\"Article 113257\"},\"PeriodicalIF\":5.7000,\"publicationDate\":\"2025-04-10\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Thin-Walled Structures\",\"FirstCategoryId\":\"5\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0263823125003519\",\"RegionNum\":1,\"RegionCategory\":\"工程技术\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"ENGINEERING, CIVIL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Thin-Walled Structures","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0263823125003519","RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, CIVIL","Score":null,"Total":0}
Dynamic stability analysis of tapered rotating beams with 2D functionally graded materials: A comparative study of Floquet theory approaches
This study investigates the dynamic and stability characteristics of rotating beams made from two-dimensional functionally graded materials (2D FGMs) with tapered geometry. Dynamics refers to the beam’s inherent vibrational behavior determined by its natural frequencies and/or time responses, and stability examines whether the system’s response remains bounded (stable) or becomes unbounded (unstable) under periodic excitation. The material properties are defined using a power law distribution model. The stiffness and mass matrices are derived based on the principle of virtual energy and evaluated using Bernoulli–Euler beam theories. Unlike previous studies, which often focus on single approaches, this research employs Floquet theory with three distinct techniques to evaluate the state transition matrix (STM), offering a comprehensive comparative analysis. The techniques investigated are the first-order step approximation, the improved integration method, and the second-order step approximation. The comparison identifies the most efficient approach in terms of accuracy and computational time, addressing limitations of existing methods. The impact of mean rotating speed, hub radius, dynamic amplitude factor, functionally graded (FG) material indexes, and taper ratio on the stability characteristics of the rotating 2D FGMs tapered beam is thoroughly analyzed. The results provide valuable insights into the dynamic behavior and stability of such beams, guiding the design and optimization of advanced rotating beam structures. The results indicate that the second-order approximation for computing the transition matrix achieves higher accuracy in predicting the instability boundaries compared to the first-order approximation, while being less time consuming than the improved integration method.
期刊介绍:
Thin-walled structures comprises an important and growing proportion of engineering construction with areas of application becoming increasingly diverse, ranging from aircraft, bridges, ships and oil rigs to storage vessels, industrial buildings and warehouses.
Many factors, including cost and weight economy, new materials and processes and the growth of powerful methods of analysis have contributed to this growth, and led to the need for a journal which concentrates specifically on structures in which problems arise due to the thinness of the walls. This field includes cold– formed sections, plate and shell structures, reinforced plastics structures and aluminium structures, and is of importance in many branches of engineering.
The primary criterion for consideration of papers in Thin–Walled Structures is that they must be concerned with thin–walled structures or the basic problems inherent in thin–walled structures. Provided this criterion is satisfied no restriction is placed on the type of construction, material or field of application. Papers on theory, experiment, design, etc., are published and it is expected that many papers will contain aspects of all three.