Test methods room-temperature cracking

Figure 3 shows the load (P) - load line displacement (5) records obtained from fracture tests at room temperature and at quasi-static conditions (low loading rates) of propylene homopolymer, PPO, and thee controlled-rheology PPs. The mechanical response for all the materials presented clearly elastic-plastic behaviour and this justifies the use of the EPFM multiple specimen method to evaluate the fracture behaviour. In addition, all the curves deviated from linearity and at a certain deflection level, sudden instability occurred and the specimen broke in two halves. The difference in stiffness is due to the different initial crack lengths. 

For the monomer polymerization at room temperature, the adhesive was augmented with a redox system of 3% BP and 0.75% DMA. To study, explain, and predict the development of the elastic failure of the polymer in the adhesive interlayer, an improved method of investigating adhesive layer crack resistance with modeling of the formation and growth of a crack at the adhesive-honded joint loading was used [119]. Five adhesive-bonded joints with the adhesive mixture compositions shown in Table 3.1 were subjected to static tests for crack resistance at room temperature. The characteristics of the static crack resistance of the adhesive-bonded joint Kic is the coefficient of the stresses intensity Gic is the intensity of the elastic energy release ic is the opening in the crack tip) were determined at the moment of onset of the crack in double-cantilever specimens DCB (Fig. 3.5). The specimen cantilevers were made of PMMA of TOCH type. 

Using equipment shown in Techniace TC description, the critical strain for several chemicals was measured. Data are included in Table 3. It is evident that the chemical resistance of alloy is better than that of high impact ABS. Also, the cracking test by brake fluid was performed using method shown in Figure 2. After molded part was tapped, the brake fluid was poured to the whole tapped part and the occurrence of cracking at room temperature was examined. The results are included in Table 4. 

Japanese standard JIS 2657-1995 testing method for spalling of refractory bricks and insulating firebrics. The brick is placed into the furnace at a distance equal to two thirds the brick s length, and after 15 min in the furnace, it is cooled down at room temperature or in water. The appearance of cracks and spalling and chipping is fixed. 

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