Instability analysis of the results of trapezoidal method tear strength test
To explore the instability of tear force results caused by the isosceles trapezoid bottom edge of trapezoidal specimens,according to GB/T 3917.3-2009 Textile-Tear properties of fabrics-Part 3:Determination of tear force of trapezoid-shape test specimens,the isosceles trapezoid bottom edge lengths of specimens are 104,100,and 96 mm respectively,and four different woven fabrics are tested.The results show that the tear force when the bottom edge length of the trapezoidal specimens is 104 mm is lower than that when the bottom edge length of the trapezoidal specimens is 100 mm,and also lower than that when the bottom edge length is 96 mm.When the bottom edge is too long,the clamping angle is larger,and the result of the tear force is smaller.The shorter the bottom edge,the smaller the clamping angle,and the stronger the tear force.