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

1999 Fiscal Year Final Research Report Summary

• Project/Area Number: 09555304
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 展開研究
• Research Field: Aerospace engineering
• Research Institution: KAGOSHIMA NATIONAL COLLEGE OF TECHNOLOGY
• Principal Investigator: KOGURE Haruyoshi SCHOOL OF GENERAL SCIENCE, KAGOSHIMA NATIONAL COLLEGE OF TECHNOLOGY, ASSISTANT PROFESSOR, 一般科目(物理), 助教授 (30106116)
• Co-Investigator(Kenkyū-buntansha): SHIBA Koujiro SCHOOL OF INFORMATION ENGINEERING, KAGOSHIMA NATIONAL COLLEGE OF TECHNOLOGY, ASSISTANT PROFESSOR, 情報工学科, 助教授 (40178893) ; DOUGOME Kazuhide SCHOOL OF INFORMATION ENGINEERING, KAGOSHIMA NATIONAL COLLEGE OF TECHNOLOGY, ASSISTANT PROFESSOR, 情報工学科, 助教授 (90217612) ; OKABAYASHI Takumi SCHOOL OF CIVIL ENGINEERING, KAGOSHIMA NATIONAL COLLEGE OF TECHNOLOGY, PROFESSOR, 土木工学科, 教授 (40044630) ; NAKIYAMA Yasuhiro SCHOOL OF MECHATRONICS ENGINEERING, KAGOSHIMA NATIONAL COLLEGE OF TECHNOLOGY, ASSISTANT PROFESSOR, 電子制御工学科, 助教授 (40222179) ; KODA Akira SCHOOL OF INFORMATION ENGINEERING, KAGOSHIMA NATIONAL COLLEGE OF TECHNOLOGY, ASSISTANT PROFESSOR, 情報工学科, 助教授 (90225368)
• Project Period (FY): 1997 – 1999
• Keywords: SEAMS FASTENE WITH RIVETSLINE / PRESSURIZED AIRPLANE' S BODY / SHELL CONSTRUCTION / BREAKE DOWN OF AIRPLANE / METALLIC FATIGUE / ULTRASONIC EMISSION / PRESTRESSING TECHNIQUE / MULTISITE-CRACKING

Research Abstract

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.