Damage evolution

Figure 5 Damage evolution in FRP vessel by means of characteristic AE classes.

Zhang, Y., et al., Damage Evolution and Recovery on Both Si and C Sublattices in Al-Implanted 4H-SiC Studied by Rutherford Backscattering Spectroscopy and Nuclear Reaction Analysis, J. Appl. Phys., Vol. 91, No. 10, 2002, pp. 6388-6395. 

Shih, C.J., Meyers, M.A., Nesterenko, V.F., Chen, S.J., Damage evolution in dynamic deformation of silicon carbide, Acta. Mater., 48, 2399-2420, 2000. 

E. Acar et al Uncertainty Analysis of Damage Evolution Computed through Microstructure-Property Relations, ASME 34th Design Automation Conference (DAC). NY, New York (2008)... 

M.D. Dighe et al Effect of loading condition and stress state on damage evolution of silicon particles in an Al-Si-Mg-Base cast alloy. Metall. Matls. Trans. A 33, 555-565 (2002)... 

M.F. Horstemeyer et al Modeling stress state dependent damage evolution in a cast Al-Si-Mg aluminum alloy. Theor. App. Fracture Mech. 33, 31 —47 (2000)... 

Generally, when testing materials with a nonlinear stress-strain behavior, the tests should be conducted under uniform stress fields, such that the associated damage evolution is also uniform over the gauge section where the material s response is measured. Because the stress field varies with distance from the neutral axis in bending tests, uniaxial tension or compression tests are preferred when characterizing the strength and failure behavior of fiber-reinforced composites. 

The micromechanical experiments in a SEM, characterize the damage evolution on preselected areas of film on substrate systems. 

Figure 4 shows the TS curves along with the assoeiated damage evolution of PESO at 0.05 mm/min. The specimen thickness was 20 mm and it can be seen from Figure 4(b) that the... 

Figure 4. Comparison of the (a) damage evolution and (b) the TS behaviour of PESO for different LBA ratios at 0.05 mm/min.

Figures 5(a) and 5(b) show the damage evolution and the corresponding measured TS curve of PESO at 50 mm/min. In Figure 5(a), the damage evolution is similar and is characterLsed by the abrupt rupture of the craze structure formed across the ligament area for all LBA ratios. Figure 5(b) shows that the separation distance increases with increasing LBA ratio, but the increase is much smaller than at 0.05 mm/min.

A simplified model for pit growth was first proposed by Harlow and Wei [2] and was used successfully to account for damage evolution in airframe aluminum alloys. For simplicity, the model assumed the pit to be hemispherical in shape, with radius a, and its growth (driven by an external constant-current source) would be at a... 

After a constitutive model has been chosen, calibrated, and validated for a particular fluoropolymer, it becomes as easy to perform multiaxial deformation simulations as it is to simulate uniaxial deformation. If the material model considers time dependence, temperature dependence, or damage evolution, then thermomechanical or fatigue loading can also easily be simulated. Since almost all commercial finite element (FE) software packages allow for nonlinear simulations including considerations of large deformations, the key component of performing accurate finite element simulations lies within the specification and calibration of the constitutive model. 

Figure 2. Argillites mechanical behaviour under classic tr iaxial compression tests, 2a) Triaxial test with unloading paths for determining damage evolution, 2b) Triaxial test with increasing step by step the confining pressure on the post-failure phase.

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