• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >Finite element and analytical models for load transfer calculations for structures utilizing metal and composites with large CTE differences.
【24h】

Finite element and analytical models for load transfer calculations for structures utilizing metal and composites with large CTE differences.

机译：有限元和分析模型，用于使用CTE差异较大的金属和复合材料的结构进行荷载传递计算。

获取原文
获取原文并翻译 | 示例
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Large composite structures have been increasingly used in the aviation industry. In order to achieve higher fuel efficiency, the use of light-weight, high-strength composite materials, such as carbon/epoxy, needs to be fully explored. New applications of composite materials include primary structures such as aircraft fuselages. This study dealt with thermal stresses induced in a composite aircraft fuselage, in which the fuselage skin was made of carbon/epoxy composite and was fastened to aluminum beams. These stresses resulted from the large coefficient of thermal expansion (CTE) difference and also the large temperature difference between the time of assembly, which was 75°F and the actual flight condition, which was -65°F). This temperature difference of around 140°F induced high thermal stresses, not only in the fasteners but also in the aluminum beams and composite panels.;The two main objectives of the study are as follows: (1) To investigate the thermally induced stresses in the aluminum beams. (2) To investigate the feasibility of thermally isolating the aluminum beams from the composite fuselage skins.;An experimental program was conducted to measure the strains on the top surface of an aluminum beam, which was fastened to the composite panel from thermal loads due to temperature difference and CTE mismatch. An approach was also designed to study the effects of the length of the aluminum beam on stresses. An analytical model was developed to evaluate the fastener load transfer and the thermally induced stress within the fastened aluminum/composite assemblies. Five parameters were used to develop an analytical model to calculate the load transfer between the aluminum/composite hybrid structures: equivalent area of the aluminum beam and composite panel, equivalent temperatures of the aluminum beam and composite panel, and equivalent fastener stiffness were determined using three-dimensional finite element analysis.;An attempt has been made to study the effect of fastener diameter, fastener spacing, material of the metallic beam, size of the metallic beam, thickness of the composite panel on the five parameters required to find the load transfer so that a relation could be established for a working engineer to determine these parameters without doing any finite element work. Equations correlating the five parameters with geometric and material properties were provided.
机译：大型复合结构已越来越多地用于航空业。为了获得更高的燃油效率，需要充分探索使用轻质，高强度的复合材料，例如碳/环氧树脂。复合材料的新应用包括飞机机身等主要结构。这项研究解决了复合飞机机身产生的热应力，其中机身蒙皮由碳/环氧复合材料制成，并固定在铝梁上。这些应力是由较大的热膨胀系数（CTE）差异以及组装时的温度差异（75°F与实际的飞行状态差异-65°F）引起的。这个大约140°F的温度差不仅在紧固件中而且在铝梁和复合板中都引起高热应力。；研究的两个主要目标如下：（1）研究在热应力下的热应力。铝梁。 （2）研究从复合机身蒙皮上热隔离铝梁的可行性。;进行了一个实验程序，以测量铝梁顶表面上的应变，该应变是由于热载荷而固定在复合面板上的。温差和CTE不匹配。还设计了一种方法来研究铝梁长度对应力的影响。开发了一个分析模型来评估紧固件的载荷传递和紧固的铝/复合材料组件内部的热应力。使用五个参数建立分析模型以计算铝/复合混合结构之间的载荷传递：使用三个参数确定铝梁和复合板的等效面积，铝梁和复合板的等效温度以及等效紧固件刚度三维有限元分析；已尝试研究紧固件直径，紧固件间距，金属梁的材料，金属梁的尺寸，复合板的厚度对找到载荷传递所需的五个参数的影响这样就可以为工作的工程师建立一种关系来确定这些参数，而无需进行任何有限元的工作。提供了将五个参数与几何和材料特性相关联的方程。

著录项

  • 作者

    Meka, Uday Sankar.;

  • 作者单位

    Wichita State University.;

  • 授予单位 Wichita State University.;
  • 学科 Aerospace engineering.
  • 学位 M.S.
  • 年度 2007
  • 页码 172 p.
  • 总页数 172
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号