Experimental analysis on membrane wrinkling under biaxial load – Comparison with bifurcation analysis

Abstract

a b s t r a c tThis paper presents a detailed experimental study of the formation and evolution of the wrinkle pattern that form in flat elastic and isotropic membranes under the action of in-plane tension. The experiments were carried out on a cruciform specimen stretched along two uncoupled axes using various loading paths. The wrinkled shapes of the membrane were digitized by using a full-field measurement based on the fringe analysis method.Over this experiment, several phenomena were observed: the mechanism of wrinkle division, the influence of the membrane thickness on the wrinkle pattern, and the reproducibility of a kinematic configuration of wrinkles.The main result is that non-unique wrinkle shapes have been observed over repeated experiments for nominally identical boundary conditions. The uncertainty of the experimental wrinkle shape has been explained using comparison with the results of a post-buckling finite element analysis.

Tensile Instability in a Thick Elastic Body

“…Next, to apply uniformly distributed traction forces to the edges of the square, we consider a cross-shaped specimen, as typically done for biaxial experiments [35,36]. More specifically, we consider a square of edges W with circles of radius R = 0.31W cut from the corners.…”

Wrinkling of extensional thin films through modified large deflection equations analytically and experimentally

“…An MTS model 42 table-top microtensile testing system with 50N (sensitivity: 0.01N) and 2KN (sensitivity: 0.5N) load cells was used to conduct the quasistatic tensile tests for simply supported rectangular thin films. 1,14,15 A high-speed camera (Basler piA640-210gm) with 100 photos/second (max. 210 photos/second at resolution ratio 640 × 480 dpi) was adopted to monitor the whole process of wrinkling from nonlinearly elastic, plastic behavior to final failure.…”

“…Pre-wrinkled conductive films have been used in micro-scaled modern technology in large-area electronics, capacitors, and polymer actuators, 7,8 and in medical surgery involved in treating wrinkling skin cases. 9 In addition to skin aging and wound healing, thin film wrinkling can be found in other fields such as semiconductor technology, 10 sandwich structure failure as face wrinkling, 11 stretchable connectors, 12 topographic matrices for cell alignment in bioengineering, metrology of material properties, 13,14 stretched thin sheets, [15][16][17][18][19] sheet metal forming and patterning, and topographical surface structuring. [20][21][22][23] From the numerous literature survey some related references are illustrated for example.…”

Modal equivalent method of full-area membrane and grid membrane

“…When the normal stresses of the membrane are considerably large, the bending moment can be neglected as its value is relatively small. While the bending moment must be considered in a wrinkle analysis, since one of the normal stress will be quite small [9]. The resultant force of the internal forces in the deflection direction is as follows:…”