scholarly journals Study on Mechanical Properties of Submunition’s Ribbon Straightening Section

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Dong-ze Qin ◽  
Wei Zhang ◽  
Shu-Yun Zhang ◽  
Tian-Ji Guo ◽  
Shui-Yuan Pei ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Numerical Simulation ◽  
Tensile Force ◽  
Physical Structure ◽  
Simulation Software ◽  
Tension Test ◽  
Response Characteristics ◽  
Experimental Scheme ◽  
Drop Velocity ◽  
Simulation Results

The humanitarian damage caused by the unexploded submunitions is one of the hot issues of concern to the international community at present. A portion of the submunition that did not explode was caused by a break at the connection between the ribbon riveting and the fuze. According to the physical structure of the submunition and the trajectory into which it was ejected, we analyzed the forces of the submunition in flight, deduced the related mathematical models, and clarify the key elements of the mechanics. In this paper, the commercial simulation software was used to calculate the mechanical properties of the ribbon. And the variation regularity between drop velocity and straightening force of ribbon are revealed. And the response characteristics of different material ribbon with different sizes of riveting holes and riveting joints under tensile action were simulated. The simulation results show that, in the trajectory environment with 30 m/s~55 m/s typical stream speed, the tensile force of the ribbon is less than 300 N, and the application concentration of the connecting parts of the riveting joint and the ribbon will not cause the failure of the kevlar ribbon, but it will cause the failure of the nylon ribbon. In order to verify the variation of the tension of kevlar ribbons in different trajectory environments, we designed the experimental scheme of tension test of the ribbon straightening section of submunition and conducted experiments. Experimental results and numerical simulation results revealed the same law. This paper provides effective technical support for solving the problem of unexploded submunitions.

scholarly journals Study on Occurrence Mechanism of Coal Pillar in L-Shaped Zone during Fully Mechanized Mining Period and Prevention Technology

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Zeng-qiang Yang ◽  
Hong-mei Wang ◽  
De-quan Sun ◽  
Xian-jian Ma ◽  
Ming-bao Xu ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Rock Burst ◽  
Dynamic Load ◽  
Static Load ◽  
Coal Pillar ◽  
Simulation Software ◽  
In Situ Investigation ◽  
Simulation Results ◽  
Occurrence Mechanism

In order to study the occurrence mechanism of rock burst in L-shaped zone during a fully mechanized mining period, the No. 705 working face which is located in Baojishan Colliery is taken as a typical engineering background. By means of in situ investigation, theoretical analysis, numerical simulation, in situ tests, and relevant monitoring methods, the occurrence mechanism of rock burst and corresponding prevention technology are studied. The results show that a coal pillar with some confining pressure in the L-shaped zone is established by FLAC3D numerical simulation software, and the numerical simulation results indicate that the change in static load has a greater effect than dynamic load on coal pillar unstable failure; the static load plays a role in storing energy, and dynamic load plays a role in inducing rock burst; the bolt-mesh-cable support and high-pressure water jet unloading combined technology is put forward to prevent rock burst in roadways, and the numerical simulation results show that stress distribution of surrounding rock meets the model of strong-soft-strong (3S) structure, and the moment distribution is reasonable. In the follow-up mining, a limit value of coal fines is used to determine that this measure is a reasonable method to prevent rock burst. The study conclusions provide theoretical foundation and new guidance for preventing rock burst by synergistic effect technology in roadways.

Effect of Dies Temperature on Mechanical Properties of Hot Stamping Square-Cup Part for Ultra High Strength Steel

2010 ◽  
Vol 129-131 ◽  
pp. 390-394
Author(s):  
Cheng Xi Lei ◽  
Zhong Wen Xing ◽  
Hong Ya Fu
Keyword(s):  
Mechanical Properties ◽  
Numerical Simulation ◽  
Hot Stamping ◽  
High Strength ◽  
Hot Forming ◽  
Forming Process ◽  
Stamping Process ◽  
Ultra High Strength Steel ◽  
Mechanical Properties Testing ◽  
Simulation Results

The numerical simulation of hot-stamping process was carried out for UHSS square-cup parts, and the influence of dies temperature on the hot-stamping process was anlysised. Besides, through the microstructure analysis and mechanical properties testing of the formed parts, effects of dies temperature on microstructures and mechanical properties of hot-stamping square-cup parts were obtained. The experiment and simulation results showed that the mechanical properties of the UHSS are strongly dependent on the temperature, so the dies temperature is one of the most important parameters that have to be taken into account in designing the hot-forming dies and the hot-forming process.

scholarly journals Numerical Simulation of Dynamic Response Characteristics of Cutting Coal and Rock by a Roller Coal Cutter

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Kesong Fan ◽  
Yutong Feng ◽  
Ruoyang Kong ◽  
Hua Wei ◽  
Wenlong Jiao ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Numerical Experiments ◽  
Simulation Software ◽  
Dynamic Responses ◽  
Average Speed ◽  
Response Characteristics ◽  
Whole Process ◽  
Different Types ◽  
Finite Element Numerical Simulation ◽  
Dynamic Response Characteristics

Currently, the identification technology of rock-coal medium is not reliable and practical, so we cannot judge the cutting state of coal-winning machine in real time. Different dynamic responses over different medium types of rock-coal can indirectly reflect the physical and mechanical parameters of rock-coal. In this study, we establish the 3-D numerical model of cutting the rock and coal by the finite element numerical simulation software in which we obtain the whole process of numerical simulation of the roller cutting coal, mudstone, and sandstone, where different dynamic responses counterpart different types of rock and coal by means of numerical experiments. The results show that when the drum keeps the average speed of cutting coal and medium forward, the instantaneous speed which is close to the average speed will have a small jump. The average speed and the torque in the cutting process can be considered as good indices to evaluate the rock and coal types. The torque from high to low is as follows: sandstone, mudstone, and coal. The average speed from high to low is as follows: coal, mudstone, and sandstone. If the portion of rock is more, the torque is higher and the average speed is lower during cutting the roof foot. This research is helpful for identifying rock-coal medium types by using related instrument to record the dynamic responses of rock-coal medium types.

The through Arch Rib Road Bridge Numerical Simulation of Blasting Demolition

2014 ◽  
Vol 533 ◽  
pp. 175-180
Author(s):  
En An Chi ◽  
Chun Ming Xie ◽  
Ming Sheng Zhao ◽  
Jun Yang ◽  
Tie Jun Tao
Keyword(s):  
Mechanical Properties ◽  
Numerical Simulation ◽  
Simulation Method ◽  
Design Phase ◽  
Important Means ◽  
Simulation Results ◽  
Concrete Materials ◽  
Structure Collapse ◽  
Concrete Model ◽  
Collapse Process

In order to ensure one through arch rib road bridge blasting demolition will go well, using separate common node reinforced concrete model, numerical simulate the process of bridge collapsed and disintegrate, at the same time, analyze the stress state of steel and concrete unit in detail. The simulation results show that separate common node model could reflect the mechanical properties difference of steel and concrete materials; destruction of the support part of bridge and joint parts reserved , meanwhile, blasting treatment of the joint parts of derrick and arches, also arch center derrick and deck beams, arch springing hinge inside pier reserved on the left, it can ensure the bridge collapsed and broken fully, and can reduce the stack height of bridge collapsed in the river. The research considers that researching on structure collapse process by numerical simulation method not only reappear the process of collapse, but also forecast collapse result in schematic design phase. It will become the important means of study the structure mechanics process of blasting demolition and guide assisted the design of structure blasting demolition, which has important engineering practical value.

Application of Numerical Simulation on Cast-Iron Pneumatic Hammer Housing

2011 ◽  
Vol 474-476 ◽  
pp. 432-435
Author(s):  
Guo Fa Mi ◽  
Li Lin Chen ◽  
Bao Zhong Liu ◽  
Hai Yan Wang
Keyword(s):  
Numerical Simulation ◽  
Cast Iron ◽  
Solidification Process ◽  
Casting Process ◽  
Simulation Software ◽  
Gating System ◽  
Pneumatic Hammer ◽  
Shrinkage Defects ◽  
Simulation Results ◽  
D Model

The Pro/E software was used to generate 3-D model of pneumatic hammer housing casting. The solidification process of the casting was simulated by the numerical simulation software, View Cast. The location and scale of the shrinkage defects were shown in the results. The risers were designed by the View Cast software based on the simulation results. The reasonable risers were obtained after the optimization on the numerical simulation. And the parameters of gating system were got according to the simulation results calculated by the gating system designing function of View Cast. Then the solidification results demonstrated that the risers and pouring system could be planned by View Cast effectually. The reasonable casting process was obtained and the process has been proofed by the productive practice.

scholarly journals Modeling of contact interface between two material layers in hybrid structures

2020 ◽  
Vol 71 (4) ◽  
pp. 419-430
Author(s):  
Nga Nguyen Thi Thu ◽  
Hung Tran Nam
Keyword(s):  
Mechanical Properties ◽  
Numerical Simulation ◽  
Bearing Capacity ◽  
Hybrid Structures ◽  
Contact Interface ◽  
Homogenization Procedure ◽  
Linear Elastic ◽  
Proposed Model ◽  
Simulation Results ◽  
The Difference

In hybrid structures, material layers of different mechanical properties are integrated to increase bearing capacity. When the difference in mechanical properties or thickness of the material layers is very large, debonding usually occurs along the interface between the two layers. This study uses a homogenization procedure combined with asymptotic algorithm applied on weaker/thinner materials to determine the interface stiffnesses for such structures. All the material layers and the interface are assumed to be linear elastic. Comprising with the available methods and numerical simulation results showed that the proposed model is more suitable with the work of the structures in reality. Furthermore, in this method the interface stiffnesses can be easily determined through the number and length of cracks and the dry or saturated state of the medium are also considered.

Numerical Simulation and Forecasting of Mechanical Properties for Multi-Component Nonferrous Dispersion-Hardened Powder Materials

2007 ◽  
Vol 534-536 ◽  
pp. 397-400
Author(s):  
Lyudmila Ryabicheva ◽  
Dmytro Usatyuk
Keyword(s):  
Mechanical Properties ◽  
Numerical Simulation ◽  
Comparative Analysis ◽  
Finite Elements ◽  
Mathematical Simulation ◽  
Input Data ◽  
Laboratory Experiments ◽  
Powder Materials ◽  
Output Data ◽  
Simulation Results

A new mathematical simulation technique for physico-mechanical properties of multicomponent powder materials is proposed in this paper. The main advantage of the technique is that finite elements representing different components are placed into a common mesh and may exchange their properties. The input data are properties of components and specified value of porosity. The output data are properties of material after sintering. The technique allows us to investigate the influence of each component of a material on the properties and distribution of properties inside the sample. The comparative analysis of materials with different compositions is based on simulation results that are well concordant with the results of the laboratory experiments.

Numerical Simulation Life Prediction of Alu- Alloy Die -Casting Dies

2012 ◽  
Vol 472-475 ◽  
pp. 2296-2303
Author(s):  
Xiong Wei Han ◽  
De Ping Chen
Keyword(s):  
Numerical Simulation ◽  
Thermal Stress ◽  
Life Prediction ◽  
Die Casting ◽  
Mathematic Model ◽  
Simulation Software ◽  
Mold Surface ◽  
Casting Technology ◽  
Stress Changes ◽  
Simulation Results

Abstract: The die casting technology has more wide application in the production of a variety of small appliances and cooking utensils. However, it is difficult to set casting technology parameters, and the life of casting die is short. In this study, the numerical simulation software was employed to simulate the aluminum mold. By analyzing temperature field, the temperature changes of the mould surface were predicted in the die-casting cycle. According to the thermal stress simulation and mathematic model, the thermal stress and strain variations were presented in the process of casting, The thermal stress changes of A, B point on the mold surface were compared under the different pouring temperature, die preheat temperature and cooling water temperature. On the basis of the simulation results, the best die casting technology parameters were selected. The life of die casting dies is predicted by mathematical model, and the simulation results agree well with the result of experiment. This study reached the conclusion is that the die life prediction method is reliable.

Numerical Simulation on Mechanical Properties of SiC/Al Co-Continuous Composites

2011 ◽  
Vol 213 ◽  
pp. 186-190 ◽  
Author(s):  
Ming Juan Zhao ◽  
Na Li ◽  
Long Zhi Zhao ◽  
Xiao Lan Zhang
Keyword(s):  
Mechanical Properties ◽  
Numerical Simulation ◽  
Stress Concentration ◽  
Yield Strength ◽  
Volume Fraction ◽  
Reinforced Composites ◽  
Ansys Software ◽  
Kelvin Model ◽  
Particle Reinforced Composites ◽  
Simulation Results

Mechanical properties of the co-continuous SiC/Al composites were simulated using the ANSYS software in this paper, and Kelvin model was adopted as SiC structure. The models of various SiC contents were calculated for composites, the influences of SiC volume fraction on the interface were analyzed. Compared with the particle reinforced composites, the influences of SiC structure on the interface and strength were investigated. The results showed that the SiC volume fraction has a certain effect on the interface of composites, the incoordination of deformation of SiC and Al causes the greater stress concentration with SiC volume fraction decreases, so that interface occurs the debonding. Compared the simulation results of co-continuous composites and particle reinforced composites, two stress-distance curves show that the stress decreases with the distance from the interface increases, and two stress-strain curves prove that the co-continuous composites have higher the yield strength and the deforming resistance.

Numerical Simulation of Pressure Limits of Gas Storage in North Area of Lamadian Oilfield

2012 ◽  
Vol 229-231 ◽  
pp. 2073-2076
Author(s):  
Dai Yin Yin ◽  
Jian Xin Lu ◽  
Shuai Wang ◽  
Cheng Li Zhang
Keyword(s):  
Numerical Simulation ◽  
Oil And Gas ◽  
Gas Storage ◽  
Simulation Software ◽  
Geological Model ◽  
Gas Oil ◽  
Practical Project ◽  
Production Cycles ◽  
Simulation Results ◽  
Oil Gas

In order to grasp the change of oil-gas interface in north area of Lamadian Oilfield and determine the conditions of gas or oil invasion during the development of gas storage, the precise geological model is established. By simulation software Eclipse immigrations of gas-oil interface are tracing simulated and cases of gas or oil invasion are monitored under various pressure differentials, based on which the limits of pressure are provided at last. Simulation results indicate that when the pressure of gas region is higher than oil region the gas invasion will happen and when the pressure differential between oil and gas region is up to 0.6 MPa the oil invasion will happen after 16 injection-production cycles. This paper is valuable to practical project applications which keep the interface stable and avoid the gas and oil invasions.

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