the relaxation modulus master curve of HDPE (trade mark YEM4803T) and the long-term burst pressure of a composite pipe

figure 4-Curve fitting to the test data of HDPE tensile relaxation modulus with time figure 4 is the relaxation modulus master curve of HDPE (trade mark YEM4803T). figure 8-Variation of long-term failure pressure with the elapsed time figure 8 shows the long-term failure pressure of a composite pipe (its name is plastic pipe reinforced by cross helically wound steel wires, and thetype is DN200 PN1.6).图4：HDPE拉伸松弛模量随时间变化的试验数据曲线拟合。图4为牌号YEM4803T的高密度聚乙烯（HDPE）的松弛模量主曲线。图8：长期失效压力随经过时间的变化规律。图8展示了某复合管材的长期失效压力，该管材名称为交叉螺旋缠绕钢丝增强塑料管材，型号为DN200 PN1.6。