scholarly journals Numerical Analysis and Dynamic Response of Optimized Composite Cross Elliptical Pressure Hull Subject to Non-Contact Underwater Blast Loading

2019 ◽  
Vol 9 (17) ◽  
pp. 3489 ◽  
Author(s):  
Helal ◽  
Huang ◽  
Fathallah ◽  
Wang ◽  
ElShafey ◽  
...  

Among the most important problems confronted by designers of submarines is to minimize the weight, increase the payload, and enhance the strength of pressure hull in order to sustain the hydrostatic pressure and underwater explosions (UNDEX). In this study, a Multiple Intersecting Cross Elliptical Pressure Hull (MICEPH) subjected to hydrostatic pressure was first optimized to increase the payload according to the design requirements. Thereafter, according to the optimum design results, a numerical analysis for the fluid structure interaction (FSI) phenomena and UNDEX were implemented using nonlinear finite element code ABAQUS/Explicit. The propagation of shock waves through the MICEPH was analyzed and the response modes (breathing, accordion and whipping) were discussed. Furthermore, the acceleration, displacement and failure index time histories at different locations were presented. The results showed that the greatest acceleration occurred in the athwart direction, followed by the vertical and longitudinal directions. Additionally, the first bubble pulse has a major effect on athwart acceleration. Moreover, the analysis can be effectively used to predict and calculate the failure indices of pressure hull. Additionally, it provides an efficient method that reasonably captures the dynamic response of a pressure hull subjected to UNDEX.

2020 ◽  
Author(s):  
Seddigheh Hasanpour Estahbanati ◽  
Reza Boushehri ◽  
Abbas Soroush ◽  
Omid Ghasemi-Fare

1995 ◽  
Vol 117 (2) ◽  
pp. 78-84
Author(s):  
Y. Li

Simulation of the time histories of second-order wave effects is often performed by quadratic transformation of a wave time history. By the present approach, the quadratic transformation of waves is approximated by linear combinations of the products of component wave time records and their Hilbert transforms. The computational efficiency is greatly enhanced. The efficient quadratic transformation of a time history is for the time domain solution of structural dynamic response, and can also be used as a post-processor of the frequency domain solution for obtaining statistic parameters of dynamic response.


2002 ◽  
Author(s):  
Zhengxing Liu ◽  
Hongyun Li

Based on classical laminated plate theory and Navier solutions, the control of the piezoelastic laminated cylindrical shell’s dynamic response under hydrostatic pressure is discussed in this paper. Considering the direct and inverse piezoelectric effects of piezoelectric materials and from Hamilton’s principle, the nonlinear dynamic equations of the piezoelastic laminated cylindrical shell are derived first. Using close circuit method, the charge enclosed in the piezoelectric sensor layer can be measured. Furthermore, the voltage applied on the actuator layer can be obtained based on the closed-circuit charge signal of the sensor and velocity negative feedback control algorithm. An active dynamic response control model of simply supported laminated cylindrical shells with piezoelectric sensor/actuator under various dynamic loads is established in this paper at last. Three types of loading conditions, namely sinusoidal distributed load, line load and moving point load, are considered in numerical examples to investigate the performance of the control model. The numerical results show that the active control model presented in this paper can suppress the vibration of the structure under dynamic loading effectively.


Author(s):  
Jingxia Yue ◽  
Weili Kang ◽  
Wengang Mao ◽  
Pengfei Chen ◽  
Xi Wang

Abstract Floating Storage and Regasification Unit (FSRU) becomes one of the most popular equipment in the industry for providing clean energy due to its technical, economic and environmental features. Under the combined loads from wind, wave and current, it is difficult for the prediction of the dynamic response for such FSRU-LNGC (Liquified Natural Gas Carrier) side-by-side mooring system, because of the complicated hydrodynamic interaction between the two floating bodies. In this paper, a non-dimensional damping parameter of the two floating bodies is obtained from a scaled model test. Then the numerical analysis is carried out based on the test results, and the damping lid method is applied to simulate the hydrodynamic interference between floating bodies. The dynamic response of the side-by-side mooring system including six degrees of freedom motion, cable tension and fender force are provided and analyzed. According to the comparisons between numerical results and the test results, it is shown that the proposed coupled analysis model is reliable, and the numerical analysis can properly describe the dynamic response of the multi-floating mooring system in the marine environment. Moreover, the non-dimensional damping parameter which is used in numerical analysis can act as a good reference to the dynamic response analysis of similar multi-floating mooring systems.


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