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[Objectives] As bolts and pins are important connector for installation of shipboard equipments,using properly simplified method for anti-shock evaluation can reduce the computation cost and improve the simulation efficiency. [Methods] On the basis of time domain analysis on the anti-shock property of shipboard equipment,a marine generator with a large amount of connectors (e.g. boltss and pins) is chosen as research object. Firstly,installation simulation of connection with bolts and pins is carried out to obtain the stiffness charcteristics in different phases of shock loading using busing unit, and equivalent dynamic model of equipment connection is attained. Then,simulation evaluation is made on the marine generator by time domain analysis,the results are compared with experimental data acquired from floating shock platform in order to verify the effectiveness and reliability of the simplified method. Lastly,criteria for failure evaluation of large-scale equipment connection under shock loading is attained.[Results] The deviation of obtained base loads as well as dynamic response between numerical values and experimental data is less than 10%,and the simplified simulation method for connection evaluation process is effective and reliable. [Conclusions] The findings in this paper can provide significant references for the evaluation of the anti-shock properties of equipment.

In order to accurately fit the failure criteria in JC failure model, BW failure model, and MMC failure model, numerical simulations for metal materials Q345B and 921A under various loading conditions of compression, torsion, tension were performed in this work. The variation of stresses, indicated by stress triaxiality and Lode parameter, was investigated during the fracture progress. The results indicated: (1) exclusive of torsional loading, the stress distribution varied in the cracking plane as the crack growth; (2) the average stress triaxiality and Lode parameter are more suitable for describing the stress status; (3) for specimens having the same size, the value of average stress triaxiality was dependent on metal properties. This work would provide useful knowledge for obtaining the failure criterion from material failure experiments. [ABSTRACT FROM AUTHOR]

Objective: To explore the variation and association of intestinal epithelial tight junctions, E.coli, and expression of Toll-like receptor-4 (TLR-4) and tumor necrosis factor-alpha (TNFα) in a rabbit model of non-alcoholic fatty liver disease (NAFLD)., Methods: Fourteen male New Zealand rabbits were randomly divided into two groups. The control group was given a normal diet, while the NAFLD group was given a high-fat diet. After 12 weeks, the two groups were sacrificed. Both length and width of the tight junctions of ileum epithelial cells were measured by electron microscopy. Enzyme-linked immunosorbent assay was used to detect the concentration of TNFα in venous blood serum. Location and expression of TLR-4 were observed by immunohistochemical staining. Copies of E.coli genes were measured by RT-PCR. The relationship between TNFα and tight junctions, TLR-4, and E.coli were respectively analyzed by stepwise multiple linear regression., Results: Compared with the control group, the NAFLD group has significantly shortened ileum epithelial fight junctions (t=5.031, P<0.01), increased copies of E. coli genes (t=-3.492, P<0.01), and increased ileal expression of TLR-4 (t=-44.089, P<0.01). A significant increase of TNFα was also observed in the NAFLD group (t=-17.768, P<0.01). Regression analysis showed that E.coli and intestinal epithelial tight junctions were correlated (standardized beta=-0.385), and showed a positive correlation between E. coli and TLR-4 (standardized beta=0.332 and 0.427)., Conclusion: Damage to the intestine as a physical barrier, biological barrier and immune barrier is closely related to TNFα expression, and the relation between the immune barrier and TNFα is more significant.