Effect of stiffeners on nature of post-critical deformations of thin-walled composite aircraft structures: A combined numerical-experimental study

Jerzy Bakunowicz,Przemyslaw Mazurek,Tomasz Kopecki,Tomasz Lis

doi:10.1109/icmae.2016.7549506

Jerzy Bakunowicz, Przemyslaw Mazurek + Show 2 more

Open Access

https://doi.org/10.1109/icmae.2016.7549506

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Publication Date: Jul 1, 2016
Citations: 3	License type: cc-by

Affiliation: Rzeszów University of Technology

Abstract

This paper presents results of numerical and experimental examination of thin-walled structures which model certain parts of aircraft structures subject to bending and torsion. The considered type of load and deformation corresponds to the state of such structures typical for in-flight conditions. A physical model of the analysed structure in several versions with and without stiffeners was made of composite materials. It was assumed that post-critical deformations of the structure are admissible within the limit loads. Results of non-linear numerical analyses carried out with the use of the finite element method applied to several variant structures with various types of stiffeners are compared with results of measurements taken on corresponding models.

Highlights

Scientific studies devoted to the problem of stability loss occurring in component structures of load-bearing systems used in different branches of technology are usually focused on issues connected with determining critical load values
In view of very specific nature of structures included within its scope of interest, specific standards have been adopted affecting the design development processes and assumptions concerning operating conditions
Two fundamental objectives were set for the abovepresented study devoted to experimental and numerical analysis of several design solutions of a typical fragment of thin-walled aircraft structure

Summary

INTRODUCTION

Scientific studies devoted to the problem of stability loss occurring in component structures of load-bearing systems used in different branches of technology are usually focused on issues connected with determining critical load values. In view of very specific nature of structures included within its scope of interest, specific standards have been adopted affecting the design development processes and assumptions concerning operating conditions One of such rules, applicable to structures made of metallic materials still dominating in the aircraft industry, provides for admissibility of post-critical deformations in selected types of structures within the range of predetermined operating load limits (e.g. paragraph 23.305 in [1]). The base on which such credibility can be founded is the rule of uniqueness of solutions according to which there is a one-to-one correspondence between distribution of the reduced stress and the deformation state This type of verification is important in the early stage of design, and would be beneficial for structures which became airborne [13]. Presented results of research are consecutive follow-up of post-buckling analysis of composite thin-walled aeronautical structures [14, 15, 16]

OBJECTIVE

NUMERICAL ANALYSES

SUMMARY AND CONCLUSIONS