공학논문석사 공학논문석사 공학논문석사. 모델룸 내부 폭발내충격 응답 해석 모델룸 내부 폭발내충격 응답 해석 모델룸 내부 폭발내충격 응답 해석 모델룸 내부 폭발내충격 응답 해석 한국해양대학교 대학원 한국해양대학교 대학원 한국해양대학교 대학원 한국해양대학교 대학원.
본 논문은 이환수 선생님의 공학석사 논문으로 승인되었습니다. 한국해양대학교 대학원 조선해양시스템공학과. 선박 구획 내부 폭발 시 선박의 생존성을 높이기 위해 피해 면적을 제한해야 하며, 피해가 인접 구획으로 확산되는 것을 방지하기 위한 BHB(Blast Hardened Bulkhead) 설계 및 성능 검증 기술이 개발됐다. 지속적인 홍수를 방지하려면 이것이 필요합니다.
본 연구에서는 내부폭발에 따른 폭발강화격벽의 거동을 평가하는 기술을 개발하기 위해 MMALE(Multi-Material Arbitrary Lagrangian Eulerian)과 FSI(Fluid-Structure)를 이용하여 폭발강화격벽 및 접합부를 평가하였다. LS-DYNA 코드의 상호작용) 분석 기법 내부 행동 폭발. 본 연구에서는 거동해석기법을 검증하고 격벽모델의 충격응답 특성을 파악하기 위해 축소 및 부분모델챔버에서 격벽 내부 폭발시험에 대한 내부 폭발충격응답해석을 수행하였다.
Introduction
TNO conducted the full-scale internal explosion test of the BHB through the internal explosion test using a retired naval vessel (Galle & Erkel, 2002), as shown in Fig. 3, and DSTO, also, the internal explosion test of the part model of the cross-section of the real part. , as shown in Fig. Internal blast tests at various scales were conducted using the real-scale compartment of the naval vessel, etc., as shown in Fig.
3 Internal explosion test of decommissioned ship and BHD model by TNO (Galle & Erkel, 2002). a) part model of DSTO (b) real scale in US. 4 Internal explosion test of a part model by DSTO (Raymond, 2001) and a full bulkhead model in the USA. BHB's self-development requires effective analysis, design and verification techniques based on the complete internal explosion test.
5, were used to develop the shock response analysis technique of BHB under internal blast. In this study, the impact response analysis of 5 main part models for the indoor reduced-scale chamber explosion test was carried out as the research basis for the real-scale explosion test, the structural behavior analysis technique was verified, and also revealed their shock response characteristics.
Internal Blast Test of Chamber Models
Bulkhead models 1~3 were used for the first internal burst test, and bulkhead models 4~5 for the second. Two types of bulkheads, such as plain and curtain types, were considered for the internal burst test of partial chamber model, as shown in Table 2. Internal burst test and shock response results of HE and LE TNT charges were considered and compared with each other.
The final test was the close internal blast for the rupture criterion of bulkhead material and weld effect with double HE TNT charge. It could be found that the damage response of bulkhead structure with relatively thin plate, 2.0 mm, was very sensitive to the welding effect. Each end of braces was torn away only in the reverse direction curtain plate type in this partial chamber model blast test.
To determine the fracture criterion in the partial chamber shot model, a high-precision internal explosion test was performed, in which the entire shot was torn off from the shot heel attached to the cartridge and most of the upper and lower cartridge parts, including along the weld line of the shot. , as shown in Fig. b) curtain plate type BH with reverse direction. 12 Damage configurations of a partial chamber shot under internal explosion test with 2 HE TNT at distance L/16.
Modeling of Shock Response Analysis of Chamber Models
The inserted plate was contacted to the inside of the cartridge using the CONTACT _SURFACE_TO_SURFACE option, and welded along the centerline to the cartridge using the CONSTRAINT_NODE_SET option, as shown in Fig. Partial and continuous welding of the sponson part of the plate inserted into the cartridge in the reduced-scale model chamber was handled with the CONSTRAINT_SPOTWELD option, as shown in Fig. The weld effect was addressed by increasing the thickness of the weld bead and decreasing the failure stress in the adjacent strip close to the bead, as shown in Fig.
In reduced scale chamber dish, dish was torn away along the bead, as the dish was very thin. Air ALE solid element was modeled to surround the chamber and bulkhead structures, and FSI analysis technique was applied to the air and charge MMALE and chamber and bulkhead structure using CONSTRAINED_. Some stress-strain curves of mild steel (SS41) and high-tensile steel (AH36) with a short strain range were obtained by the static and high-speed tensile test, and curve fitting process was applied to the originals, as shown in Fig.
Extended stress-strain curves were proposed for the high strain rate in the case of near internal explosion, such as range distance L/16 and 2 HE TNT charge, using Cowper and Symonds equation, as shown in Fig. was adopted for the fracture of structure in the shock response analysis and failure was applied to the chamber structure according to the element size to its thickness and welding effect. Pressure and acceleration responses were measured at the locations on reduced scale and partial room bulkheads, as in Fig.
Properties Mild steel (SS41) High tensile steel (AH36). a) Original SS41 & AH36 s test curve with curve fitting process.
Shock Response Analysis of Chamber Models
21 Propagation of shock pressure in partial chamber model according to standoff distance for HE TNT charge. Fig. 25 and 26 illustrate the configurations of plastic deformation and deformation response at the partial chamber curtain and common type bulkheads according to the spacing distance HE TNT charge, respectively, and Figs. 27 and 28, their plastic load responses at the center, corners of the bulkhead and the end of braces, and deformation responses along the vertical, horizontal and diagonal directions from the center at the bulkhead to confirm their response according to bulkhead type and rack -off distance HE TNT charging, respectively
25 Plastic strain response configurations in partial chamber shields by HE TNT charge standoff distance. 26 Configurations of the deformation response in the partial chamber shields according to the standoff distance of the HE TNT charge. 27 Plastic strain responses in partial chamber shields by HE TNT charge standoff distance.
28 Deformation responses in partial chamber bulkheads according to HE TNT charge distance. As expected, the maximum and range of plastic strain of the common bulkhead in the center of the bulkhead increased with the decrease in the distance between the HE TNT charge and the bulkhead, and large plastic strains also occurred in the corners of the bulkhead with the decrease in the distance between the HE TNT charge and the bulkhead as the shock pressure was applied to the corners of the reflected wave. Those of the curtain type appeared relatively smaller than those of the ordinary type bulkhead at stand-off distance L/2 of HE TNT charge.
Unexpectedly, the deformation magnitude and range at the common-type bulkhead did not increase linearly in accordance with the decrease in the distance between the HE TNT charge and the bulkhead, and they decreased and increased again as the separation distance of the HE TNT charge from L/2, L/4, and L/8, as shown in fig. In the case of the curtain-type bulkhead with reverse direction at the distance L/2 of the HE TNT charge, the stiffeners buckled and their only end parts were torn away in the neighborhood near the weld bead in the internal blast simulation and test, as shown in Fig. 29 Damage configurations of curtain type partial chamber bulkhead under HE TNT charge with reverse direction and distance L/2.
30 Damage configurations of common type partial chamber dish under 2 HE TNT charge at standing distance L/16. Under the whole internal blast test of partial chamber models, pressure and acceleration responses of ordinary type shelter at standoff distance L/2 & L/4 and curtain one at standoff distance L/2 were typically compared with those of internal blast tests, as shown in Fig. 36 Acceleration responses between experiment and simulation with HE TNT in ordinary type dish at standoff distance L/2.
37 Pressure responses between experiment and simulation with HE TNT in an ordinary shot at distance L/4. 38 Acceleration responses between experiment and simulation with HE TNT in an ordinary shot at distance L/4. 39 Pressure responses between experiment and simulation with HE TNT in curtain type bulkhead at distance L/2.
40 Acceleration responses during experiment and simulation with HE TNT in a partition wall at a flat distance L/2.
Conclusion
