Figure 1: the main parts of the material testing machine

Figure 2: Typical tensile test specimen, showing a reduced gage section and enlarged shoulders

Figure 3: as seen, the tensile testing machine shows an error message (Err. L/C), indicated by the arrow

Figure 4: shows how the error message disappears when disconnecting the cable

Figure 5: in order to avoid any financial expenses, Eng. Diaa Ghassan (from private sector) volunteered to solve the technical problems

Figure 6:the electronic chart of the Signal conditional interface card, shows the damage electrical fuses F1 and F2

Figure 7:the geometric dimensions of type II sample according to ASTM D638

Figure 8:the preparation process of HDPE samples in the Materials Testing Laboratory

Figure 9:tensile test results for HDPE samples (1 & 2) prepared in the Materials Testing Laboratory

Figure 10: the typical Stress-strain curve of pure HDPE

Figure 11:(a): Stress-Strain Curve for HDPE samples with 1mm cracks (b): Stress-Strain curve for pure HDPE sample containing a single crack

Figure 12: image taken by a micro-camera showing the gas bubbles in the rupture area after the end of the tensile test for samples 1&2, prepared in the Material Testing Laboratory

Figure 13:tensile test results for HDPE samples 3 & 4, prepared in the Materials Testing Laboratory

Figure 14: tensile Successful test for HDPE sample № 12, prepared and tested in the Materials Laboratory by tensile testing machine H50KS