DESIGN OF AN ENERGY-INTENSIVE PNEUMATIC HAMMER BASED ON THE PHYSICAL SIMULATION OF THE HAMMER–SOIL INTERACTION

2021 ◽  
Vol 57 (1) ◽  
pp. 86-95
Author(s):  
V. V. Chervov ◽  
I. V. Tishchenko ◽  
A. V. Chervov ◽  
Yu. V. Vanag
Keyword(s):  
Physical Simulation ◽  
Pneumatic Hammer

Mathematical and Physical Simulation of Indoor Daylighting: A Case Study

1997 ◽  
Vol 26 (3) ◽  
pp. 129-137
Author(s):  
S. R. Bandyopadhyay ◽  
Biswanath Ray
Keyword(s):  
Physical Simulation

scholarly journals Research on Measurement Method of Parachute Scanning Platform Based on MEMS Device

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 402
Author(s):  
Ning Liu ◽  
Tianqi Tian ◽  
Zhong Su ◽  
Wenhao Qi
Keyword(s):  
Physical Simulation ◽  
Inertial Sensors ◽  
Rotational Velocity ◽  
Attitude Measurement ◽  
Matlab Simulation ◽  
Scanning Angle ◽  
Reduce Development Time ◽  
Motion Parameters ◽  
Motion Characteristics ◽  
Scanning Motion

This paper studies the measurement of motion parameters of a parachute scanning platform. The movement of a parachute scanning platform has fast rotational velocity and a complex attitude. Therefore, traditional measurement methods cannot measure the motion parameters accurately, and thus fail to satisfy the requirements for the measurement of parachute scanning platform motion parameters. In order to solve these problems, a method for measuring the motion parameters of a parachute scanning platform based on a combination of magnetic and inertial sensors is proposed in this paper. First, scanning motion characteristics of a parachute-terminal-sensitive projectile are analyzed. Next, a high-precision parachute scanning platform attitude measurement device is designed to obtain the data of magnetic and inertial sensors. Then the extended Kalman filter is used to filter and observe errors. The scanning angle, the scanning angle velocity, the falling velocity, and the 2D scanning attitude are obtained. Finally, the accuracy and feasibility of the algorithm are analyzed and validated by MATLAB simulation, semi-physical simulation, and airdrop experiments. The presented research results can provide helpful references for the design and analysis of parachute scanning platforms, which can reduce development time and cost.

scholarly journals The influence of advance speed on overburden movement characteristics in longwall coal mining: insight from theoretical analysis and physical simulation

2021 ◽  
Vol 18 (1) ◽  
pp. 163-176
Author(s):  
Penghua Han ◽  
Cun Zhang ◽  
Zhaopeng Ren ◽  
Xiang He ◽  
Sheng Jia
Keyword(s):  
Physical Simulation ◽  
Impact Load ◽  
Main Roof ◽  
Longwall Face ◽  
Mine Safety ◽  
Efficient Production ◽  
Time Space ◽  
Mining Pressure ◽  
The Impact ◽  
Advance Speed

Abstract The advance speed of a longwall face is an essential factor affecting the mining pressure and overburden movement, and an effective approach for choosing a reasonable advance speed to realise coal mine safety and efficient production is needed. To clarify the influence of advance speed on the overburden movement law of a fully mechanised longwall face, a time-space subsidence model of overburden movement is established by the continuous medium analysis method. The movement law of overburden in terms of the advance speed is obtained, and mining stress characteristics at different advance speeds are reasonably explained. The theoretical results of this model are further verified by a physical simulation experiment. The results support the following conclusions. (i) With increasing advance speed of the longwall face, the first (periodic) rupture interval of the main roof and the key stratum increase, while the subsidence of the roof, the fracture angle and the rotation angle of the roof decrease. (ii) With increasing advance speed, the roof displacement range decreases gradually, and the influence range of the advance speed on the roof subsidence is 75 m behind the longwall face. (iii) An increase in the advance speed of the longwall face from 4.89 to 15.23 m/d (daily advancing of the longwall face) results in a 3.28% increase in the impact load caused by the sliding instability of the fractured rock of the main roof and a 5.79% decrease in the additional load caused by the rotation of the main roof, ultimately resulting in a 9.63% increase in the average dynamic load coefficient of the support. The roof subsidence model based on advance speed is proposed to provide theoretical support for rational mining design and mining-pressure-control early warning for a fully mechanised longwall face.

scholarly journals Experimental and Numerical Study of the Effects of the Reversal Hot Rolling Conditions on the Recrystallization Behavior of Austenite Model Alloys

Metals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 26
Author(s):  
Krzysztof Muszka ◽  
Mateusz Sitko ◽  
Paulina Lisiecka-Graca ◽  
Thomas Simm ◽  
Eric Palmiere ◽  
...  
Keyword(s):  
Microstructure Evolution ◽  
Hot Rolling ◽  
Strain Path ◽  
Physical Simulation ◽  
Numerical Study ◽  
Kinematic Hardening ◽  
Process Window ◽  
Recrystallization Behavior ◽  
Full Field ◽  
Strain Reversal

The experimental and numerical study of the effects of the recrystallization behavior of austenite model alloys during hot plate rolling on reverse rolling is the main goal of the paper. The computer models that are currently applied for simulation of reverse rolling are not strain-path-sensitive, thus leading to overestimation of the processing parameters outside the accepted process window (e.g., deformation in the partial austenite recrystallization region). Therefore, in this work, a particular focus is put on the investigation of strain path effects that occur during hot rolling and their influence on the microstructure evolution and mechanical properties of microalloyed austenite. Both experimental and numerical techniques are employed in this study, taking advantage of the integrated computational material engineering concept. The combined isotropic–kinematic hardening model is used for the macroscale predictions to take into account softening effects due to strain reversal. The macroscale model is additionally enriched with the full-field microstructure evolution model within the cellular automata framework. Examples of obtained results, highlighting the role of the strain reversal on the microstructural response, are presented within the paper. The combination of the physical simulation of austenitic model alloys and computer modeling provided new insights into optimization of the processing routes of advanced high-strength steels (AHSS).

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