Experimental and Numerical Study on Softened Inclusions Equivalent Method for Impacted Stiffened Panel Skin
- PDF / 2,880,875 Bytes
- 20 Pages / 439.37 x 666.142 pts Page_size
- 65 Downloads / 203 Views
Experimental and Numerical Study on Softened Inclusions Equivalent Method for Impacted Stiffened Panel Skin Xin Wang1 · Jun Huang1 · Xiao Huang2 · Yuru Su1 · Zengshan Li1 · Riming Tan1 Received: 27 July 2020 / Accepted: 12 November 2020 © Springer Nature B.V. 2020
Abstract This paper presented and validated a method of softened inclusions for impact damage of stiffened panel skin. The impacted laminates with different impact energy were cut into strips according to the damage area from C-scan results. Then, the stiffness distribution in the impact damage area was obtained by testing the tensile and compressive stiffness of the strip specimens. The results showed that the stiffness reduction in some delamination was independent of the impact energy. The testing results also suggest that the damaged area was divided into three regions with different degrees of reduced stiffness. An equivalent method was proposed to replace the damage area with softened inclusions in impacted laminates. To validate the effectiveness and accuracy of the method, softened inclusions was introduced into the finite element models of stiffened panels with impacted skin. And the strain distribution of the models were compared with the test results under the same conditions. The results showed good agreement between the models and experiments. Keywords Softened inclusion · Composites stiffened panel · Impact damage · Residual stiffness
1 Introduction Carbon Fibre Reinforced Plastics (CFRP) composite materials have found increasing industrial applications in the last decades, especially in the aerospace and ground transport fields, due to their high ratio of stiffness and strength to weight. However, although the usage of CFRP materials can effectively reduce the weight of the structure in theory, it still faces many limitations in practical application. Compared with metal materials, the most serious weakness of CFRP materials is its high sensitivity to imperceptible defects and damages, which come from manufacturing defects and uncertainties, as well as in-service or accidental damages [1]. One of the most dangerous situations is that a damaged composite structure after in-service loads may
* Zengshan Li [email protected] 1
School of Aeronautic Science and Engineering, Beihang University, Beijing 100191, China
2
Chengdu Aircraft Design & Research Institute, Chengdu 610091, China
13
Vol.:(0123456789)
Applied Composite Materials
remain or return to its original shape without any detectable damage (Barely Visible Damage (BVD)), while it has suffered massive internal damage [2, 3]. Although damage occurs at material level, the overall structural performance will be influenced [1]. In addition to the reduction of residual strength, there are also changes in buckling characteristics, overall stiffness response and even in loadingtransfer pattern [5]. A typical structural analysis object is stiffened-panel structure. In recent years, considerable research has been devoted to the experimental analysis of the effect of damage on th
Data Loading...
