scholarly journals Study on the Influence of Explosive Types on Rod Jet

2021 ◽  
Vol 2132 (1) ◽  
pp. 012051
Author(s):  
Bingzhe Wang ◽  
Liyun Xie ◽  
Zhounan Guo

Abstract In order to study the influence of explosive type on the rod jet formation of energetic composite liner, the process of rod jet formation of this liner is numerically simulated by using finite element analysis and multi-material Euler algorithm. In this paper, the rod jet formation and penetration performance of the liner are studied and analyzed by combining relevant theories and simulation calculation, and the influence law of explosive type on rod jet formation and target penetration thickness is obtained. In this paper, the stability of rod jet formed by this kind of model is verified by numerical simulation, and the influence law of explosive type on rod jet is obtained by simulating the collected data such as effective mass, tip velocity and jet length of rod jet and the equivalent target penetration thickness obtained by the quasi steady incompressible ideal fluid theory of jet penetration; it provides data support and design basis for the application of new explosives in energetic composite liner in the next stage.

2014 ◽  
Vol 941-944 ◽  
pp. 2547-2552
Author(s):  
Yuan Yuan Zhou ◽  
Jun Lin Wan ◽  
Ya Wei Zhao ◽  
Qin Jian Mao

Experiment research aiming at the anti-explosion capability of the refuge chamber is a complex work with high costs. By using finite element analysis, however, could avoid this issue and implement the simulation and analysis more effectively. Based on transient dynamics approach, numerical simulation calculation and analysis of the dynamic response of the refuge chamber under the impact caused by gas explosion are presented in this paper. The results indicate that, when the refuge cabin under specified explosion impact wave stress, the maximum stress of the cabin is 370.8MPa,which is under the ultimate strength, and the maximum impact wave deformation of the cabin is 9.43mm, which is under the maximum permissive deformation (20mm), therefore the rigidity and the strength of the cabin both meet the demands. The refuge chamber presented in this paper, which remain the integrity of the cabin and the safety of the structure under specified explosion impact, has good anti-explosion ability, and could implemmet the emergency risk avoiding effectively.


2017 ◽  
Vol 45 (1) ◽  
pp. 71-84 ◽  
Author(s):  
Alexey Mazin ◽  
Alexander Kapustin ◽  
Mikhail Soloviev ◽  
Alexander Karanets

ABSTRACT Numerical simulation based on finite element analysis is now widely used during the design optimization of tires, thereby drastically reducing the time investment in the design process and improving tire performance because it is obtained from the optimized solution. Rubber material models that are used in numerical calculations of stress–strain distributions are nonlinear and may include several parameters. The relations of these parameters with rubber formulations are usually unknown, so the designer has no information on whether the optimal set of parameters is reachable by the rubber technological possibilities. The aim of this work was to develop such relations. The most common approach to derive the equation of the state of rubber is based on the expansion of the strain energy in a series of invariants of the strain tensor. Here, we show that this approach has several drawbacks, one of which is problems that arise when trying to build on its basis the quantitative relations between the rubber composition and its properties. An alternative is to use a series expansion in orthogonal functions, thereby ensuring the linear independence of the coefficients of elasticity in evaluation of the experimental data and the possibility of constructing continuous maps of “the composition to the property.” In the case of orthogonal Legendre polynomials, the technique for constructing such maps is considered, and a set of empirical functions is proposed to adequately describe the dependence of the parameters of nonlinear elastic properties of general-purpose rubbers on the content of the main ingredients. The calculated sets of parameters were used in numerical tire simulations including static loading, footprint analysis, braking/acceleration, and cornering and also in design optimization procedures.


2021 ◽  
Vol 11 (9) ◽  
pp. 3770
Author(s):  
Monica Tatarciuc ◽  
George Alexandru Maftei ◽  
Anca Vitalariu ◽  
Ionut Luchian ◽  
Ioana Martu ◽  
...  

Inlay-retained dental bridges can be a viable minimally invasive alternative when patients reject the idea of implant therapy or conventional retained full-coverage fixed dental prostheses, which require more tooth preparation. Inlay-retained dental bridges are indicated in patients with good oral hygiene, low susceptibility to caries, and a minimum coronal tooth height of 5 mm. The present study aims to evaluate, through the finite element method (FEM), the stability of these types of dental bridges and the stresses on the supporting teeth, under the action of masticatory forces. The analysis revealed the distribution of the load on the bridge elements and on the retainers, highlighting the areas of maximum pressure. The results of our study demonstrate that the stress determined by the loading force cannot cause damage to the prosthetic device or to abutment teeth. Thus, it can be considered an optimal economical solution for treating class III Kennedy edentation in young patients or as a provisional pre-implant rehabilitation option. However, special attention must be paid to its design, especially in the connection area between the bridge elements, because the connectors and the retainers represent the weakest parts.


2008 ◽  
Vol 22 (05) ◽  
pp. 553-560 ◽  
Author(s):  
WU-JIE YUAN ◽  
XIAO-SHU LUO ◽  
PIN-QUN JIANG ◽  
BING-HONG WANG ◽  
JIN-QING FANG

When being constructed, complex dynamical networks can lose stability in the sense of Lyapunov (i. s. L.) due to positive feedback. Thus, there is much important worthiness in the theory and applications of complex dynamical networks to study the stability. In this paper, according to dissipative system criteria, we give the stability condition in general complex dynamical networks, especially, in NW small-world and BA scale-free networks. The results of theoretical analysis and numerical simulation show that the stability i. s. L. depends on the maximal connectivity of the network. Finally, we show a numerical example to verify our theoretical results.


1994 ◽  
Vol 116 (4) ◽  
pp. 550-555 ◽  
Author(s):  
M. Gremaud ◽  
W. Cheng ◽  
I. Finnie ◽  
M. B. Prime

Introducing a thin cut from the surface of a part containing residual stresses produces a change in strain on the surface. When the strains are measured as a function of the depth of the cut, residual stresses near the surface can be estimated using the compliance method. In previous work, the unknown residual stress field was represented by a series of continuous polynomials. The present paper shows that for stress states with steep gradients, superior predictions are obtained by using “overlapping piecewise functions” to represent the stresses. The stability of the method under the influence of random errors and a zero shift is demonstrated by numerical simulation.


2012 ◽  
Vol 204-208 ◽  
pp. 4455-4459 ◽  
Author(s):  
Liu Hong Chang ◽  
Chang Bo Jiang ◽  
Man Jun Liao ◽  
Xiong Xiao

The explicit dynamic finite element theory is applied on the collision of ships with buoys for computer simulation. Using ANSYS/LS-DYNA finite element analysis software, the numerical simulation of the collision between the ton ship and the buoy with different structures and impact points. The collision force, deformation, displacement parameters and the weak impact points of a buoy are obtained. Based on the numerical simulation results, analysis of buoys and structural collision damages in anti-collision features are discussed, and several theoretical sugestions in anti-collision for the design of buoy are provided.


2013 ◽  
Vol 554-557 ◽  
pp. 630-637 ◽  
Author(s):  
Martin Grüner ◽  
Marion Merklein

Aluminium alloys show a great potential for lightweight constructions due to their high strength and low density but the production of this material is very energy consuming. Also the recycling of aluminium alloys, e.g. chips from the milling process, shows different challenges. Beside contamination by cooling lubricant and oxidation of the surface of the chips the melting and rolling process for new semi finish products needs a high amount of energy. TEKKAYA shows a new approach for recycling of aluminium alloy chips by an extrusion process at elevated temperatures producing different kinds of profiles. A new idea is the production of components directly out of chips using severe plastic deformation for joining of the chips similar to the accumulative roll bonding process in sheet metal forming. In a first approach aluminium alloy chips out of a milling process were uniaxial compressed with different loads inside an axisymmetric tool installed in a universal testing machine. The compressed chip disks subsequently were tested with two experiments to gain information on their stability. First experiment is a disk compression test with the disk standing on its cylindrical surface, giving information on the stability perpendicular to the compression direction. Second experiment is a stacked disk compression test with three disks to investigate the stability parallel to compression direction. During all three tests force and displacement values are recorded by the universal testing machine. These data are also processed to calculate or identify input parameters for the numerical investigations. For numerical simulation ABAQUS in conjunction with the Drucker-Prager-Cap material model, which is often used for sintering processes, seems to be a good choice. By numerical simulation of the experiments and comparison with the experiments input parameters for the material model can be identified showing good accordance. This material model will be used in future numerical investigations of an extrusion process to identify tool geometries leading to high strains inside the material and by this to an increased stability of the parts.


2015 ◽  
Vol 777 ◽  
pp. 8-12 ◽  
Author(s):  
Lin Zhen Cai ◽  
Cheng Liang Zhang

HuJiaDi tunnel construction of Dai Gong highway is troublesome, the surrounding-rock mass give priority to full to strong weathering basalt, surrounding rock integrity is poor, weak self-stability of surrounding rock, and tunnel is prone to collapse. In order to reduce disturbance, taking advantage of the ability of rock mass, excavation adopt the method of "more steps, short footage and strong support". The excavation method using three steps excavation, The excavation footage is about 1.2 ~ 1.5 m; The surrounding rock bolting system still produce a large deformation after completion of the first support construction, it shows that the adopted support intensity cannot guarantee the stability of the tunnel engineering. Using ABAQUS to simulate tunnel excavation support, optimizing the support parameters of the tunnel, conducting comparative analysis with Monitoring and Measuring and numerical simulation results, it shows that the displacement - time curves have a certain consistency in numerical simulation of ABAQUS and Monitoring and Measuring.


2014 ◽  
Vol 1004-1005 ◽  
pp. 1474-1477
Author(s):  
Ze Ying Yang ◽  
Jia You Liu ◽  
Yi Dong Zhang ◽  
Jian Bo Qu

By numerical simulation and contrasting with experimental conclusions, mechanical models in every loading stage of CFRP reinforced concrete bridge deck were established. The results showed that, numerical simulation results of non-prestressed bridge decks fitted corresponding test results well. The stiffness of prestressed structures had been greatly improved than non-prestressed structures, so the high strength performance of CFRP had been used more effectively.


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