Tear strength characteristics of laminated envelope composites based on single edge notched film experiment

• Tear strength was tested on the fabric laminated envelope with single notched edge.
• A new physical model was created to compute the tear strength of the envelope film.
• The calculation of the arithmetical tensile deformation of crack tip was proposed.
• The del-zone stress distribution was obtained with plane stress analysis process.
• The calculative tear strength deviation was lower than stress intensity factor method.

In order to analyze tear strength of laminated envelope reinforced by Kevlar-plain woven fabric, a new physical model is developed to calculate the initial single edge notched (SEN) shape. The arithmetical displacement method is proposed to calculate the stress distribution of the crack tip. Then three types of specimens are tested. It is found that the tear strength between the physical model and experiment tests is approximate, and the deviation is lower than 5%. When compared with the stress intensity factor, this model is more accurate and suitable, and the initial crack length ratio could even reach 0.60.