Single lap shear tests. Figure 2.5 LSS of the dry welded joints a) as a function of temperature; b) before and after hygrothermal conditioning Figure 2.5 presents the LSS of tested specimens. The error bars represent plus and minus one standard deviation. The LSS of dry welded joints as a function of the test temperature is presented in Figure 2.5.a. The LSS decreases linearly with the temperature with a discontinuity around Tg. The LSS of joints tested at 82°C is 26% lower than that of joints tested at room temperature. The slope of the linear fit between 21°C and 82°C is -0.1159 MPa/°C. In the vicinity of Tg, the drop of LSS seems more important. The reduction of the LSS with temperature above Tg follows the same trend with a similar slope (-0.1161 MPa/°C). The LSS of specimens tested before and after hygrothermal aging is shown in Figure 2.5.b. As explained in section 2.4.3, some aged specimens were tested at 21°C and others were tested at the conditioning temperature. At 21°C, 82°C and 90°C, the LSS is not significantly different between wet and dry specimens. It is therefore concluded that regardless of the test temperature and the hygrothermal conditions, the LSS of welded joints is not impacted by moisture absorption but only depends on the test temperature.
