Modeling Viscoelastic Damping in Civil Structures

模拟土木结构中的粘弹性阻尼

• 批准号: 9978752
• 负责人: Daniel Inman
• 金额: $ 19.97万
• 依托单位: Virginia Polytechnic Institute and State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-10-01 至 2000-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9978752&HistoricalAwards=false
• 关键词: Modeling; Viscoelastic; Damping; Civil; Structures

Modeling Viscoelastic Damping in CiAl StructuresCo-Pi's Daniel J. Inman and Eric M. AustinThe goal of this research is to examine the nature of viscoelastic damping mechanisms in structures and structural components at all levels from basic constitutive relations to final usage in finite element codes. Many finite element codes incorporate simple forms of damping matrices, but as the performance demands of civil structures increases, the importance of more accurate damping matrices increases dramatically.Viscoelastic damping mechanisms are difficult quantities to model, yet the damping these mechanisms produce determines the major features of the time response of a system due to wind, traffic, or earthquake loads, and thus it is often a key design issue. Finite element codes are the chief tools for predicting vibration response, yet the least developed part of finite element methodology is how damping is incorporated into dynamic finite element models. Most current commercial codes readily available to practicing engineers include damping only in an ad hoc, nonphysical way. Here it. is proposed to investigate three promising methodologies that will allow damping to be included in finite element codes that is both physically based yet computationally compatible with existing finite element practice.The primary goal of this research is to explore a new approach to incorporating the effects of viscoelasticity into standard finite element models for time-domain analyses. This observer-based approach is intended to be an alternative to the internal-variable methods that have appeared in recent years. The basic concept is that internal variables used to model time-domain viscoelastic behavior are similar to unmeasurable states, and this research is aimed at bringing decades of controls research to bear on this problem.I

CiAl结构中的粘弹性阻尼建模。Austin本研究的目的是研究粘弹性阻尼机制的性质，在结构和结构部件的各个层次，从基本的本构关系，最终使用有限元代码。许多有限元代码包含简单形式的阻尼矩阵，但随着土木结构性能要求的增加，更精确的阻尼矩阵的重要性急剧增加。粘弹性阻尼机制是难以建模的量，然而这些机制产生的阻尼决定了系统在风、交通或地震荷载下的时间响应的主要特征，因此它通常是关键的设计问题。有限元代码是预测振动响应的主要工具，然而有限元方法中最不发达的部分是如何将阻尼纳入动态有限元模型。大多数现行的商业代码容易获得的执业工程师包括阻尼只在特设，非物理的方式。在这里，它。建议调查三个有前途的方法，将允许阻尼被包括在有限元代码，这是物理上的基础，但计算兼容与现有的有限元practice.The主要目标，这项研究是探索一种新的方法，将粘弹性的影响纳入标准的有限元模型的时域分析。这种基于内部变量的方法旨在替代近年来出现的内部变量方法。其基本概念是，用于模拟时域粘弹性行为的内部变量类似于不可测状态，本研究旨在将数十年的控制研究用于解决这个问题。