复合材料疲劳试验的改进载荷寿命系数法研究
发布时间：2018-12-09 15:08
【摘要】：在过去的30多年,飞机主要结构上的先进复合材料使用量已显著增加。随着先进通用航空运输试验计划的实施,美国国家航空航天局(NASA)和美国联邦航空管理局(FAA)在1994年新增了通用和商用航空复合材料的使用。金属和复合材料在损伤力学和耐久性问题上存在很大的区别,但复合材料和金属需要满足相同要求的结构完整性、安全性和耐用性。虽然复合材料结构的优点很多,但由于在大型结构、交互失效机理、温湿度的敏感性和疲劳分散性等方面缺乏经验,使得其相关试验论证变得十分困难。本文研究的总体目标是在保证可靠性的同时,考虑经济和试验持续时间,采用改进载荷寿命系数法,求得复合材料的载荷放大系数(LEF)和试验持续时间(N0),并为复合材料的机体结构论证提供指导。具体内容包括:(1)概述复合材料飞机结构耐久性试验,介绍其积木式试验方法以及分散性分析方法,并且详细介绍已有复合材料飞机结构耐久性疲劳试验方法—寿命系数法、载荷放大系数法和极限强度法,重点推导改进载荷寿命系数法,并依此法求得复合材料的LEF和N0,在保证相同可靠性和置信度的前提下,能够有效地缩短复合材料飞机结构的全尺寸试验持续时间。(2)研究铺层方式为[45/0/-45/90]s的CCF300/BA9916-II复合材料层合板拉-拉载荷的疲劳行为和规律,使用本文研究的改进载荷寿命系数法,得到复合材料层合板在B基准上的疲劳寿命和剩余强度的形状参数,进而求得该复合材料的LEF和N0。并将试验结果与已有的复合材料统计结果相较,验证改进载荷寿命系数法的正确性。该方法通过使用改进联合威布尔分布分析分散性,简化了求解复合材料的LEF和N0的过程。(3)研究铺层方式为[45/-45/0/0/-45/90/0/90/45/0]s的T300/BMP316新型复合材料层合板(无孔和含孔)在拉-拉载荷的疲劳行为及规律,运用已验证的改进载荷寿命系数法求解其LEF和N0,得出部件的试验件数和孔径对复合材料层合板的LEF和N0的影响。
[Abstract]:Over the past 30 years, the use of advanced composite materials in the aircraft's main structures has increased significantly. With the implementation of the Advanced General Air Transport Test Program, NASA (NASA) and Federal Aviation Administration (FAA) added the use of general and commercial aviation composite materials in 1994. There are great differences in damage mechanics and durability between metal and composite materials, but the structural integrity, safety and durability of composites and metals need to meet the same requirements. Although there are many advantages of composite structure, due to the lack of experience in large structure, mutual failure mechanism, sensitivity of temperature and humidity and fatigue dispersion, it is very difficult to test and prove it. The overall goal of this paper is to obtain the load magnification factor (LEF) and the test duration (N0) of the composite material by using the improved load-life coefficient method while ensuring the reliability and taking into account the economic and experimental duration. And provides the guidance for the body structure demonstration of the composite material. The main contents are as follows: (1) the durability test of composite aircraft structure is summarized, and the building block test method and dispersion analysis method are introduced. The life factor method, load magnification factor method and limit strength method are introduced in detail. The improved load life coefficient method is mainly derived. According to this method, the LEF and N0 of composite materials are obtained. With the same degree of reliability and confidence, It can effectively shorten the duration of full-scale test of composite aircraft structures. (2) the fatigue behavior and regularity of tensile and tensile loads of CCF300/BA9916-II composite laminates with [45 / 0 / -45 / 90] s laminates are studied. Using the improved load life coefficient method studied in this paper, the fatigue life and the shape parameters of residual strength of composite laminates on B datum are obtained, and the LEF and N0 of the composite are obtained. The experimental results are compared with the existing statistical results of composite materials to verify the correctness of the improved load life coefficient method. This method uses improved joint Weibull distribution to analyze dispersion. The process of solving the LEF and N0 of composite materials is simplified. (3) A new type of T300/BMP316 composite laminates (without and with holes) is studied in the form of [45 / -45 / 0 / 0 / 45 / 90 / 0 / 90 / 90 / 90 / 45 / 0] s. Fatigue behavior and regularity of tension-pull load, The LEF and N0 are solved by using the improved load life coefficient method, and the effects of the number of test parts and the aperture of the components on the LEF and N0 of composite laminates are obtained.
【学位授予单位】：南昌航空大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：V250.2
本文编号：2369588
[Abstract]:Over the past 30 years, the use of advanced composite materials in the aircraft's main structures has increased significantly. With the implementation of the Advanced General Air Transport Test Program, NASA (NASA) and Federal Aviation Administration (FAA) added the use of general and commercial aviation composite materials in 1994. There are great differences in damage mechanics and durability between metal and composite materials, but the structural integrity, safety and durability of composites and metals need to meet the same requirements. Although there are many advantages of composite structure, due to the lack of experience in large structure, mutual failure mechanism, sensitivity of temperature and humidity and fatigue dispersion, it is very difficult to test and prove it. The overall goal of this paper is to obtain the load magnification factor (LEF) and the test duration (N0) of the composite material by using the improved load-life coefficient method while ensuring the reliability and taking into account the economic and experimental duration. And provides the guidance for the body structure demonstration of the composite material. The main contents are as follows: (1) the durability test of composite aircraft structure is summarized, and the building block test method and dispersion analysis method are introduced. The life factor method, load magnification factor method and limit strength method are introduced in detail. The improved load life coefficient method is mainly derived. According to this method, the LEF and N0 of composite materials are obtained. With the same degree of reliability and confidence, It can effectively shorten the duration of full-scale test of composite aircraft structures. (2) the fatigue behavior and regularity of tensile and tensile loads of CCF300/BA9916-II composite laminates with [45 / 0 / -45 / 90] s laminates are studied. Using the improved load life coefficient method studied in this paper, the fatigue life and the shape parameters of residual strength of composite laminates on B datum are obtained, and the LEF and N0 of the composite are obtained. The experimental results are compared with the existing statistical results of composite materials to verify the correctness of the improved load life coefficient method. This method uses improved joint Weibull distribution to analyze dispersion. The process of solving the LEF and N0 of composite materials is simplified. (3) A new type of T300/BMP316 composite laminates (without and with holes) is studied in the form of [45 / -45 / 0 / 0 / 45 / 90 / 0 / 90 / 90 / 90 / 45 / 0] s. Fatigue behavior and regularity of tension-pull load, The LEF and N0 are solved by using the improved load life coefficient method, and the effects of the number of test parts and the aperture of the components on the LEF and N0 of composite laminates are obtained.
【学位授予单位】：南昌航空大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：V250.2
【参考文献】
相关期刊论文 前1条
1 胡静伟;余明;万小朋;;复合材料层板结构疲劳失效数值仿真研究[J];计算机仿真;2012年04期
，本文编号：2369588
本文链接：https://www.wllwen.com/kejilunwen/hangkongsky/2369588.html
