Influence of Strengthening Material Behavior and Geometry Parameters on Mechanical Behavior of Biaxial Cruciform Specimen for Envelope Material

Zhipeng Qu; Houdi Xiao; Mingyun Lv; Xihe Wang; Pengfei Wang; Lei Xu

doi:10.3390/ma12172680

Influence of Strengthening Material Behavior and Geometry Parameters on Mechanical Behavior of Biaxial Cruciform Specimen for Envelope Material

Materials (Basel). 2019 Aug 22;12(17):2680. doi: 10.3390/ma12172680.

Authors

Zhipeng Qu¹, Houdi Xiao², Mingyun Lv², Xihe Wang³, Pengfei Wang³, Lei Xu³

Affiliations

¹ School of Aeronautic Science and Engineering, Beihang University, Beijing 100083, China. quzhipeng@buaa.edu.cn.
² School of Aeronautic Science and Engineering, Beihang University, Beijing 100083, China.
³ Aviation Industry Corporation (AVIC) Special Vehicle Research Institute, Jingmen 448035, China.

Abstract

The stratospheric airship envelope material is operated in biaxial stress, so it is necessary to study the in-plane biaxial tensile strength. In this paper, a theoretical model is developed to evaluate the mechanical properties of in-plane biaxial specimens. Being applied to the finite element analysis, the theoretical model is employed to evaluate the influence of strengthening material behavior (E*) and geometry parameters on the mechanical behavior in the central. The follows results are drawn: (i) smaller the length of the central region (L_cen), E* and larger the central region corner radius (r) contribute to smaller coefficient of variation (CV); (ii) smaller L_cen and larger E* contribute to smaller stress concentration factor (k), k in the limit state of r is larger than that in other conditions. (iii) The CV and k under stress ratio of 1:1 are smaller than those under other stress ratios. The study can provide a useful reference for the design of biaxial specimens.

Keywords: cruciform; geometry parameters; stress concentration factor; variation coefficient.