RESEARCH ON EVALUATION FOR AN ORIGINAL ENGINEERING WORKING MEASURE AGAINST TO THE "MUTISITE-CRACKING" OF SEAMS BETWEEN A PANEL AND ANOTHER PANEL FASTENED BY RIVETSLINE

铆钉连接板与板间接缝“多点开裂”的原始工程施工措施评价研究

• 批准号: 09555304
• 负责人: KOGURE Haruyoshi
• 金额: $ 6.98万
• 依托单位: KAGOSHIMA NATIONAL COLLEGE OF TECHNOLOGY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09555304/
• 关键词: SEAMS FASTENE WITH RIVETSLINE; PRESSURIZED AIRPLANE' S BODY; SHELL CONSTRUCTION; BREAKE DOWN OF AIRPLANE; METALLIC FATIGUE; ULTRASONIC EMISSION; PRESTRESSING TECHNIQUE; MULTISITE-CRACKING; アコースティックエミッション; ソナグラム; PC工法; ソナグラフ

The acsident of JAL's "jumbo-plane" and the acsident occurred in HAWAII are fresh in our memory. These acsidents are caused by the "multisite-cracking" of seeam between a panel and another panel fastened with rivetsline. These acsidents had given us very serious shock for the meaning that the "failsafety-mythology" against to the cracking of pressurized airplane's body was broken thoroughly. So, getting of new engineering working measure against to the "multisite-cracking" is very important matter.The pupose of this research is to corroborate the validity of new engineering working measure against to this "multisite-cracking which have been proposed by head investigator. The gist of this proposal is, by using the prestressing technique which is very popular one in the concrete handling field, to make flames and stringers of the airplane's body work onestep harder and ensure the "failsafety" against to the cracking of pressurized airplane's body.To corroborate the validity of this proposal, a computer controled pulling type weariness testing machine was hand made. After the cracks had broken out on the test pieces, ultrasonic sound emission was measured by the sound analyzing system composed of ultrasonic microphon, ultrasonic sonagrph and color printer, on each experiment.Cause by the dimension of testing macine was too small, and by the stiffnes of material (normal aluminum) used for the test pieces was insufficient, expected result was not obtained.On the other hand, samely to corroborate the validity of the proposal, photoelasitic experiments has been executed.On this way, we get prospectfull result.

日本航空公司的“巨型飞机”事故和发生在夏威夷的事故令人记忆犹新。这些缺陷是由板与板之间用铆钉线紧固的接缝处的“多点开裂”引起的。这些事件给了我们很大的震撼，意味着抗机体增压开裂的“故障安全神话”被彻底打破。因此，针对“多点开裂”提出新的工程措施是一项十分重要的工作，本研究的目的就是要验证课题组组长提出的针对“多点开裂“的新的工程措施的有效性。该方案的要点是利用混凝土施工中普遍采用的预应力技术，使机体的火焰和纵梁一次性加强工作，保证机体在受压时的“失效安全性”，防止机体开裂，为验证该方案的有效性，手工制作了计算机控制的拉力式疲劳试验机。在试件破裂后，用超声传声器、超声声发射仪和彩色打印机组成的声分析系统，对每一次试验进行超声声发射测量，由于试验机尺寸过小，材料的刚度大另一方面，同样为了证实该提议的有效性，进行了光弹实验，取得了较好的效果。