scholarly journals Theoretical Study on Radial Distribution Laws of Rock Mass Damage Factors under Decoupled Charge Blasting

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Qiang Pan ◽  
Jichun Zhang ◽  
Shuangying Zheng ◽  
Hongchao Shi ◽  
Zhanfeng Fan
Keyword(s):  
Stress Wave ◽  
Radial Distribution ◽  
Optimization Design ◽  
Damage Zone ◽  
Effective Elastic Modulus ◽  
Critical Value ◽  
Attenuation Rate ◽  
Combined Action ◽  
Distribution Laws ◽  
Decoupling Coefficient

In this paper, the radial distribution laws of damage factors under decoupled charge blasting are studied for the optimization design of blasting parameters. Through defining the critical radial decoupling coefficient, the damage zone around the borehole is partitioned and the characteristics are described. Based on the damage factor defined by Taylor’s effective elastic modulus, the formulas of the radial distribution laws of damage factors are derived by the attenuation law of stress wave and the theory of thick-walled cylinder, respectively, which are then superposed to obtain the formula under the combined action of explosion stress wave and quasistatic gas. Experimental verification indicates that the theoretical values, which have a good correlation with the test data and are of high accuracy, can characterize the radial distribution laws of damage factors and estimate the damage range. When a radial decoupling coefficient is less than the critical value, the attenuation rate of damage factors firstly increases and then decreases with the increase of distance, and a serious damage zone is caused. Conversely, it decreases gradually, and the serious damage zone is not caused. Therefore, on the premise of stable detonation, it is necessary to apply an appropriate radial decoupling coefficient which is larger than the critical value to smooth or presplit blasting.

Finite Element Optimization Design on the Back Frame of the Jaw Crusher PC5282

2012 ◽  
Vol 472-475 ◽  
pp. 2024-2028
Author(s):  
Sheng Guo ◽  
Wei Ping Huang ◽  
Nian Qing Guo
Keyword(s):  
Finite Element ◽  
Optimization Design ◽  
Static Load ◽  
Three Dimensional ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Element Analysis ◽  
Jaw Crusher ◽  
Distribution Laws ◽  
Set Up

According to the main parameters of the jaw crusher PC5282, structure of the back frame was designed, and three-dimensional model of the back frame was also set up. Finite element analysis of the back frame under static load was done in COSMOSWORKS. The distribution laws of stress, displacement and deformation were revealed. Optimization design was also finished, and the weight of the back frame was reduced.

The Design of Emergency Rescue Equipment for Agricultural Motor-Pumped Wells

2014 ◽  
Vol 488-489 ◽  
pp. 1104-1107
Author(s):  
Kai Bao Wang ◽  
Wen Kai Ma ◽  
Xian Ge Meng ◽  
Rui Feng Wang ◽  
Xing Fu Wang
Keyword(s):  
Mechanical System ◽  
Optimization Design ◽  
Simulation Analysis ◽  
Design Method ◽  
Dynamics Analysis ◽  
Small Space ◽  
Emergency Rescue ◽  
Combined Action ◽  
Set Up ◽  
Negotiation Mechanism

A wide variety of motor-pumped wells were used in agricultural in our daily life. Considering the service situation, the motor-pumped well was exposed to the air usually. With the condition, the falling accidents of underage children are reported frequently. It is extremely complicated to rescue the children trapped in the narrow and small space. The emergency rescue equipment based on optimization design method and dynamics analysis is introduced in the paper. This Motor-pumped well Rescue Equipment with the carrying platform can be controlled by the flexible rope to adapt to different rescue site. With the protection of umbrella support structure, the equipment completes combined action by dragging the manipulator; the equipment has been set up scalable obstacle negotiation mechanism so that it can adapt to the Motor-pumped well larger than 350 mm in diameter. In the research, the virtual prototype technology was used to simulate the kinematics and dynamics characteristics of the mechanical system. The feasibility of the design scheme of mechanical system was proved with the simulation analysis results. The equipment has advantages of the structure is compact, safe and reliable, easy to use. The research of the emergency rescue equipment for agricultural motor-pumped wells can be regarded as the reference of the related research.

Numerical Investigation of the Adhesive Damage Used for the Repair of A5083 H11 Aluminum Structures by Composites Patches

2019 ◽  
Vol 44 ◽  
pp. 22-31
Author(s):  
Kaddour Sadek ◽  
Mohammed Salah Bennouna ◽  
Benaoumeur Aour ◽  
Bel Abbès Bachir Bouiadjra ◽  
Ali Benaissa ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Aluminum Alloy ◽  
Damage Zone ◽  
Critical Value ◽  
Composite Repair ◽  
Circular Shape ◽  
Bonded Composite ◽  
Adhesive Thickness ◽  
And Performance

In addition of binding the patch to the cracked material, adhesives play an important role in bonded composite repair because they make the bridge of transfer of loads between the patch and the cracked material. Indeed, any damage in adhesives will affect the efficiency and the performance of the repaired structure by composite patches.In this paper, two different adhesive shapes were numerically investigated, using finite element method in order to estimate the damage zone area on the adhesive bonded composite repair in 5083 marine grade aluminum alloy and its effect on the efficiency and performance of the repaired structure. The obtained results proved that the circular shape causes less damage than the rectangular one for the three crack lengths chosen. Moreover, both shapes of adhesive maintain their performance repair without disband risk and without reaching the critical value defined by Ban and co-authors (Dr=0.2474). Furthermore, it is concluded that the damage zone increases with the increase of the adhesive thickness and the decrease of the patch thickness and the use of circular shape is more effective than the rectangular one for the configurations and loading conditions studied.

Finite Element Optimization Design of the Movable Jaw on PC5282 Jaw Crusher

2012 ◽  
Vol 430-432 ◽  
pp. 1614-1618
Author(s):  
Nian Qin Guo ◽  
Wei Ping Huang
Keyword(s):  
Finite Element ◽  
Optimization Design ◽  
Three Dimensional ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Element Analysis ◽  
Jaw Crusher ◽  
Distribution Laws ◽  
Set Up ◽  
Movement Simulation

According to the performance parameters of the main structure of the jaw crusher PC5282, movement simulation of its mechanism was done to get trajectory and the stress analysis. The three-dimensional model of the movable jaw was set up. On the COSMOSWORKS platform, finite element analysis of the movable jaw was finished to reveal the distribution laws of stress, displacement and deformation. The structure optimization of the movable jaw was also done to lighten the weight. All research was to provide references for improvement design of the movable jaw.

scholarly journals Analysis of the Cracking Mechanism of an Elliptical Bipolar Linear-Shaped Charge Blasting

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Bo Wu ◽  
Han Wei ◽  
Shixiang Xu ◽  
Guowang Meng ◽  
Zhen Huang ◽  
...  
Keyword(s):  
Shock Wave ◽  
Stress Wave ◽  
Wave Attenuation ◽  
Shaped Charge ◽  
Propagation Length ◽  
Energy Accumulation ◽  
Attenuation Rate ◽  
Linear Shaped Charge ◽  
Initial Shock ◽  
Cracking Mechanism

This study investigates the cracking mechanism of an elliptical bipolar linear-shaped charge blasting via theoretical analysis, experimentation, and numerical simulation. The results show that in the shaped charge blasting, due to the effect of the shaped jet in the direction of the shaped energy, a certain initial crack length is formed. In the action phase of the stress wave, the energy accumulation direction reduces the load required for crack initiation and propagation. The crack propagation length generated in the energy accumulation direction is greater than the nonenergy accumulation direction. The load value of the initial shock wave in the shaped energy direction is significantly greater, by about 1.64 times than the nonshaped energy direction, and the peak load acting time is earlier than the nonshaped energy direction. A large amount of impact explosion energy is consumed in the area close to the charged energy explosion due to the crushing area, regardless of the charged or noncharged energy direction. In the energy accumulation direction, the shock wave attenuation rate is faster in the near explosion area and the stress wave attenuation rate is slower in the mid and far areas of the explosion. The difference in the explosion load in the mid and far areas is small. In the nonconcentrated direction, owing to the reflected compression wave, the second stress peak appears in the nonconcentrated direction. However, its value is smaller than that of the initial shock wave peak.

On the Test Method of Dynamic Characteristics of MEMS Components

2013 ◽  
Vol 562-565 ◽  
pp. 119-124 ◽  
Author(s):  
Guang He ◽  
Ya Jun Wang ◽  
Wen Rui Ma
Keyword(s):  
Strain Rate ◽  
Stress Wave ◽  
Dynamic Characteristics ◽  
Optimization Design ◽  
Static Condition ◽  
Test Method ◽  
Testing System ◽  
Split Hopkinson ◽  
Micro Electromechanical System ◽  
Design And Manufacture

The paper developed a set of small split Hopkinson pressure/tensile bar testing system (SSHPB/SSHTB) to study the dynamic characteristics of the micro-electromechanical system (MEMS) material and components, by which the dynamic characteristics of MEMS nickel material and planar S-form micro-spring were got. The dynamic Youngs modulus of LIGA nickel under the strain rate of 2×103s-1 got by the SSHPB is about 250GPa, which is slightly higher than that under static condition. The deformation peculiarity of the planar S-form micro-spring is also got by the SSHTB, which is uneven due to the spreading of the stress wave in the micro-spring. The result of the paper is valuable for providing feasible directions to the optimization design and manufacture of the MEMS components.

Structures and crystallization of vacuum-deposited amorphous Se and Sb films

1990 ◽  
Vol 48 (4) ◽  
pp. 140-141
Author(s):  
Makoto Shiojiri ◽  
Toshiyuki Isshiki ◽  
Tetsuya Fudaba ◽  
Yoshihiro Hirota
Keyword(s):  
Monte Carlo ◽  
Electron Microscope ◽  
Monte Carlo Method ◽  
Computer Program ◽  
Radial Distribution ◽  
Film Formation ◽  
Amorphous State ◽  
Two Dimensional ◽  
Amorphous Films ◽  
Binding Condition

In hexagonal Se crystal each atom is covalently bound to two others to form an endless spiral chain, and in Sb crystal each atom to three others to form an extended puckered sheet. Such chains and sheets may be regarded as one- and two- dimensional molecules, respectively. In this paper we investigate the structures in amorphous state of these elements and the crystallization.HRTEM and ED images of vacuum-deposited amorphous Se and Sb films were taken with a JEM-200CX electron microscope (Cs=1.2 mm). The structure models of amorphous films were constructed on a computer by Monte Carlo method. Generated atoms were subsequently deposited on a space of 2 nm×2 nm as they fulfiled the binding condition, to form a film 5 nm thick (Fig. 1a-1c). An improvement on a previous computer program has been made as to realize the actual film formation. Radial distribution fuction (RDF) curves, ED intensities and HRTEM images for the constructed structure models were calculated, and compared with the observed ones.

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