Abstract: Environment-assisted cracking (EAC) is one of the most serious causes of structural failure over a broad range of industrial applications including offshore structures. In EAC condition there is not a definite relation such as Paris equation in Linear Elastic Fracture Mechanics (LEFM). According to studying and searching a lot what the researchers said either a material has contact with hydrogen or any other corrosive environment, phenomenon of electrical and chemical reactions of material with its environment will be happened. In the literature, there are many different works to consider fatigue crack growing and solve it but they are experimental works. Thus, in this paper, authors have an aim to evaluate mathematically the pervious works in LEFM. Obviously, if an environment is more sour and corrosive, the changes of stress intensity factor is more and the calculation of stress intensity factor is difficult. A mathematical relation to deal with the stress intensity factor during the diffusion of sour environment especially hydrogen in a marine pipeline is presented. By using this relation having and some experimental relation an analytical formulation will be presented which enables the fatigue crack growth and critical crack length under cyclic loading to be predicted. In addition, we can calculate KSCC and stress intensity factor in the pipeline caused by EAC.
Abstract: Musculoskeletal problems are common in high
performance dance population. This study attempts to identify lower
extremity muscle flexibility parameters prevailing among
bharatanatyam dancers and analyze if there is any significant
difference exist between normal and injured dancers in flexibility
parameters. Four hundred and one female dancers and 17 male
dancers were participated in this study. Flexibility parameters
(hamstring tightness, hip internal and external rotation and
tendoachilles in supine and sitting posture) were measured using
goniometer. Results of our study it is evident that injured female
bharathnatyam dancers had significantly (p < 0.05) high hamstring
tightness on left side lower extremity compared to normal female
dancers. The range of motion for left tendoachilles was significantly
(p < 0.05) high for the normal female group when compared to
injured dancers during supine lying posture. Majority of the injured
dancers had high hamstring tightness that could be a possible reason
for pain and MSDs.