crack 
The relationship between medial crack length and normal loading was also investigated when specimens were indented by symmetrical wedges with interior angles of 30°120°.


Crack fault quantitative diagnosis based on finite element of Bspline wavelet on the interval


The modelbased forward and inverse problems in the diagnosis of structural crack faults were studied.


The forward problem is to solve the natural frequencies through a cracked structural model and the inverse problem is to quantitatively determine the crack parameters using the experimental testing frequencies.


Then, the onedimensional crack element of Bspline wavelet on the interval (BSWI) was built to solve the forward problem.


Contour plots of normalized crack location versus normalized crack size were plotted by using the first three natural frequencies as the inputs.


The intersection of the three curves predicted the normalized crack location and size.


The new method can be applied to prognosis and quantitative diagnosis of incipient crack.


Its bifurcation and chaos characteristics are analyzed with crack fault and without crack fault.


By analyzing the bifurcation plot, Poincare section plots and amplitude spectra, we found that the crack greatly influences the dynamic characteristics of the rotorbearing system.


Because of the strong effect of the nonlinear oilfilm force and crack to the system, 1/2 times, 1/3 times frequency components appear in the response spectrum map.


The effect of hydrogen on the susceptibility is more obvious in the low stress region due to the longer fracture time, which resulted in a longer time for more hydrogen to diffuse toward the crack tip.


The results showed that an interaction between stress and hydrogen at the crack tip could increase the anodic dissolution rate remarkably.


A computer program capable of calculating the hysteretic model of steel members, predicting the damage state and crack initiation, and carrying out nonlinear time history seismic analysis of steel structures is developed.


Fracture resistance on aggregate bridging crack in concrete


Utilizing the obtained load against crack opening displacement curve, the value of GIbridging at any crack extension as well as the change of GIbridging with the crack extension is examined.


It is found that GIbridging will firstly increase with the development of crack and then stay constant once the initial crack tip opening displacement reaches the characteristic crack opening displacement w0.


The results reveal that the values of GIbridging of different specimens at any crack propagation are strongly associated with the values of fracture energy of specimens.


Besides, the critical crack tip opening displacement of each specimen is calculated, too.


In certain types of soil, crack depth correlated with the number of acidproducing microorganisms and aerobic chemoorganotrophs (saprophytes).

