Development of a Numerical Model for an Expanding Tube with Linear Explosive Using AUTODYN

Choi, Min Suk; Lee, Jung-Ryul; Kong, Cheol-Won

doi:10.1155/2014/436156

Cited by 11 publications

(5 citation statements)

References 12 publications

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“…The delicate adjustments of several parameters including gaseous mixture, strength of the ignition source and turbulence of the flow are necessary to ensure successful deflagration to detonation transition. 26 Nevertheless, researchers have succeeded to create supersonic moving pressures by implementation of mild detonation fuses inside aluminium expanding tubes 27 and pentaerythritol tetranitrate (PETN) cords inside steel pipes. 25 In this study, the explosive cords (PETN, 8 and 16 g m −1 ) were mounted inside the tubes in a coaxial arrangement.…”

Section: A T E R I a L S A N D M E T H O D Smentioning

confidence: 99%

On the role of stress waves in dynamic rupture of cylindrical tubes

Mirzaei

Tavakoli

Najafi

2017

Fatigue Fract Eng Mat Struct

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A systematic experimental/computational study was performed to investigate the role of stress waves in ductile fracture of cylindrical tubes. The stress waves were created by high‐speed moving load, which was produced by detonation of explosive cord inside two intact and two pre‐flawed steel tubes. Several distinct phenomena like cyclic crack growths in Modes I and III, crack flap bulging and crack curving/branching were observed and simulated by finite element (FE) method. The FE models were composed of 3D brick elements equipped with interface cohesive elements. The analysis results showed that the crack growths in Modes I and III were governed by the detonation‐induced stress waves. The crack speeds were obtained based on the increments of cyclic crack growth and the time period of the stress waves. The estimated crack speed range was 63–230 m s−1 for the axial growth, whereas the average speed for growth in Mode III was 100 m s−1.

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Section: A T E R I a L S A N D M E T H O D Smentioning

confidence: 99%

On the role of stress waves in dynamic rupture of cylindrical tubes

Mirzaei

Tavakoli

Najafi

2017

Fatigue Fract Eng Mat Struct

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“…All of the material structural parameters were from the AUTODYN material library, and their specific values are listed in Tables 2-5 [19][20][21][22].…”

Section: Shock and Vibrationmentioning

confidence: 99%

Numerical Study on the Explosive Separation of Pyrotechnic Cutter

Xiong

et al. 2019

Shock and Vibration

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Pyrotechnic cutters are widely used in the wrapping-band connecting structures of carrier rockets. In this article, a three-dimensional (3D) finite element model of a pyrotechnic cutter is proposed to determine the influence of the explosive dynamic fracture process and the cutter blade acceleration distance on the cutting effect, using AUTODYN finite element simulation software. Numerical simulations of the cutting process reveal that the initial shear speed, the maximal speed, and the speed at which the cutter connects the rod increase linearly with increasing distance between the cutter blade and the cutting board. As the distance increases, the difference between the initial cutting speed and the maximal speed of the cutter gradually decreases and effectively disappears for a distance of 8.5 mm. At this time, the acceleration effect of the gunpowder gas on the cutter is nearly maximal. When the distance between the cutter and the connecting rod is less than 7.5 mm, the cutting time decreases significantly with increasing spacing. For distances between 7.5 mm and 8.5 mm, the distance has little effect on the cutting time as it increases. There is a small increase in the cutting time, and it can be seen that there is an optimal distance between the cutter and the cutting board during the cutting process. The cutting effect is the strongest for this distance. For the cutter studied in this article, the optimal distance was 7.5 mm. In addition, numerical studies were also performed by varying the maximal cutting diameter of the connecting rod of the pyrotechnic cutter. The discrepancy between the simulation results and actual test data was under 10%, and the simulation result for the cut state of the connecting rod was also consistent with the test result. The simulation results in this article can deepen the understanding of the action mechanism and process of the pyrotechnic cutter and reveal the maximal cutting diameter of the connecting rod of the pyrotechnic cutter under different charging conditions. This provides a reference for future cutter design optimization.

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“…Their results provide a relatively comprehensive description about the separation mechanism and the shock environment characteristics of this separation device. Mijin Choi et al (2014) preliminarily stimulated the separation process and computed the proper core loading of the expansion tube based on the AUTODYNA dynamic analysis code in combination with some separation tests. Nevertheless, their experimental and numerical procedures are only based on a specific separation device, which is inefficient and non-universal.…”

Section: Introductionmentioning

confidence: 99%

Experimental and numerical investigation on the shock characteristics of U-notched ZL205A specimens under dynamic mixed-mode loading

Ren

Lin

et al. 2018

Lat. Am. j. solids struct.

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Shock environment assessment and improvement during stage separation is an important issue of concern in aerospace engineering. This paper focuses on shock response caused by dynamic fracture of aluminum alloy separation plate, which usually undergoes mixed mode loading during separation. Based on Split Hopkinson Tensile Bar (SHTB) apparatus, five groups of U-notched ZL205A specimens with different loading angles (0°, 30°, 45°, 60°, and 90°) are designed to simulate mixed mode loading for shock characteristics testing. There piezoelectric accelerometers are used to measure the acceleration time histories, and the maximum shock response spectrum (SRS) are applied for shock data analysis. Meanwhile, the ANSYS/LS-DYNA finite element software is implemented for numerical analysis. The actual fracture angles measured from the recovered specimens are used to describe the actual fracture modes. The numerical and experimental results are in good agreement, showing that the shock response along the specimen's length and thickness directions increases with the fracture angle, while there is a slight distinction in the specimen's width direction with different fracture angles. On average, the shock response is more remarkable in pure tensile fracture mode, which is 2.6 times the pure shear fracture mode. As a result, increasing the study of shear fracture component is meaningful for the shock reduction through the structural design of separation plate.

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Development of a Numerical Model for an Expanding Tube with Linear Explosive Using AUTODYN

Cited by 11 publications

References 12 publications

On the role of stress waves in dynamic rupture of cylindrical tubes

On the role of stress waves in dynamic rupture of cylindrical tubes

Numerical Study on the Explosive Separation of Pyrotechnic Cutter

Experimental and numerical investigation on the shock characteristics of U-notched ZL205A specimens under dynamic mixed-mode loading

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