Numerical simulation of the impact load distribution of the hydraulic mechanical stepless transmission

2020 ◽  
Author(s):  
Ya-Jun Liu
Keyword(s):  
Numerical Simulation ◽  
Load Distribution ◽  
Impact Load ◽  
The Impact

scholarly journals Research on Meshing Characteristics of Shearer Walking Wheel Based on Rigid-Flexible Coupling

2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
Lirong Wan ◽  
Dejian Ma ◽  
Xin Zhang
Keyword(s):  
Load Distribution ◽  
Impact Load ◽  
Dynamic State ◽  
Transition Curve ◽  
Force Model ◽  
State Equations ◽  
Flexible Coupling ◽  
Longitudinal Load ◽  
Meshing Characteristics ◽  
The Impact

Frequent failure of the walking wheel seriously restricts the performance of the whole shearer. To reduce the failure rate and improve the working performance of the walking wheel, the meshing characteristics of the tooth pin are researched. The dynamic state equations of the walking wheel and the contact force model of tooth pin meshing are established. The rigid-flexible coupling simulation model of tooth pin meshing is built. The load distribution characteristics of the walking wheel are analyzed, as well as the effects of impact load amplitude and duration. Results show that the curve of the longitudinal load distribution coefficient (Kβ) of the contact area is W-shaped, with a maximum of 1.325 at the moment of a single tooth contact. The end of the transition curve is the most serious position of the longitudinal load imbalance at the tooth root. In addition, on the impact moment, Kβ tends to decrease and maximum stress obviously increases with the increase in impact load under 40%; the material at the contact position will fail under an extra 39% instantaneous impact load. Furthermore, with the impact load of 30%, the influence of load impact duration under 0.5 s on the meshing characteristics of the walking wheel is relatively faint. The results provide some guidance for the design optimization of the walking wheel and provide a reference for improving the reliability of the shearer.

Numerical Simulation and Experimental Study on Fluid-Filled Hemispherical Shell under Impact

2013 ◽  
Vol 364 ◽  
pp. 172-176
Author(s):  
Hui Wei Yang ◽  
Bin Qin ◽  
Zhi Jun Han ◽  
Guo Yun Lu
Keyword(s):  
Numerical Simulation ◽  
Dynamic Response ◽  
Impact Load ◽  
Elastic Recovery ◽  
Plastic Hinge ◽  
Time History ◽  
Hemispherical Shell ◽  
History Of ◽  
Local Impact ◽  
The Impact

The dynamic response of fluid-filled hemispherical shell in mass impact is studied by experiment using DHR9401. Combining the time history of impact force with experimental observation of the deformation process, it can be seen that the dynamic response can be divided into four stages: the flattening around the impact point, the forming and expanding outward of shell plastic hinge, the plastic edge region flatten by the punch, and elastic recovery. The experimental results show that: Because the shell filled with liquid, the local impact load that the shell suffered is translated into area load and loads on the inner shell uniformly, so that it has a high carrying capacity. Numerical simulation is used to study the time history of energy absorption of different shell structures. The result shows that the crashworthiness of sandwich fluid-filled shell is improved greatly. Under the certain impact energy, deformation of its inner shell is very small, which can provide effective security space.

scholarly journals Numerical Simulation on Mechanical Strength of a Wooden Golf Stick

2018 ◽  
Vol 2 (1) ◽  
pp. 13
Author(s):  
Darianto Darianto ◽  
Bobby Umroh ◽  
Amrinsyah Amrinsyah ◽  
Zulfikar Zulfikar
Keyword(s):  
Numerical Simulation ◽  
Stress Distribution ◽  
Maximum Stress ◽  
Impact Load ◽  
Golf Club ◽  
Stress And Strain ◽  
Sectional Area ◽  
Cross Sectional ◽  
Swing Speed ◽  
The Impact

In general, golf players only know the techniques used in Golf games, but do not know the golf sticks response that occurs when the ball is hit. Referred to as response is the stress and strain that arises from the impact load that occurs when the hitting member touches the ball. The objectives of this research are: (a) to analyze golf sticks response when impact occurs, and (2) to know the stress distribution that occurs in golf sticks. The golf stick design in this study uses the autodesk inventor software. The material used is Titanium for head stick and Graphite for stick rod. The basic principle of this study is based on simple swing pendulum method. The variables that will be used for simulation are: swing speed, that is difference between start and end speed, that is Δv = 272,2 m / s, impact time, which is the time when the ball touches the batter Δt = 0.0005 seconds, the volume of the head of the stick Vo = 96,727 mm<sup>3</sup>, the cross-sectional area of the stick A = 63,504 mm<sup>2</sup>, the head mass of the sticks ρ = 4620 kg / m<sup>3</sup>, and the modulus of titanium elasticity 9.6 e +10 Pa. From the simulation result on the surface of the golf club hitter is obtained as follows: σ<sub>max</sub> = 2.1231e +10 Pa at 1.231e-06 s, e<sub>max</sub> = 0.22115 m / m at 1.231e-06 s, and the maximum stress and strain is located in the area the connection between the stick and the head of the stick.

On the Distribution of Wave Impact Loads on Offshore Structures

2017 ◽  
Author(s):  
Thomas B. Johannessen ◽  
Øystein Lande ◽  
Øistein Hagen
Keyword(s):  
Model Test ◽  
Load Distribution ◽  
Impact Load ◽  
Peak Load ◽  
Offshore Structures ◽  
Impact Loads ◽  
Test Results ◽  
Wave Impact ◽  
The Impact ◽  
Crest Height

For offshore structures in harsh environments, horizontal wave impact loads should be taken into account in design. Shafts on GBS structures, and columns on semisubmersibles and TLPs are exposed to impact loads. Furthermore, if the crest height exceeds the available freeboard, the deck may also be exposed to wave impact loads. Horizontal loads due to waves impacting on the structure are difficult to quantify. The loads are highly intermittent, difficult to reproduce in model tests, have a very short duration and can be very large. It is difficult to calculate these loads accurately and the statistical challenges associated with estimating a value with a prescribed annual probability of occurrence are formidable. Although the accurate calculation of crest elevation in front of the structure is a significant challenge, industry has considerable experience in handling this problem and the analysis results are usually in good agreement with model test results. The present paper presents a statistical model for the distribution of horizontal slamming pressures conditional on the incident crest height upwave of the structure. The impact load distribution is found empirically from a large database of model test results where the wave impact load was measured simultaneously at a large number of panels together with the incident crest elevation. The model test was carried out on a circular surface piercing column using long simulations of longcrested, irregular waves with a variety of seastate parameters. By analyzing the physics of the process and using the measured crest elevation and the seastate parameters, the impact load distribution model is made seastate independent. The impact model separates the wave impact problem in three parts: – Given an incident crest in a specified seastate, calculate the probability of the crest giving a wave impact load above a threshold. – Given a wave impact event above a threshold, calculate the distribution of the resulting peak load. – Given a peak load, calculate the distribution of slamming pressures at one spatial location. The development of the statistical model is described and it is shown that the model is appropriate for fixed and floating structures and for wave impact with both columns and the deck box.

Analysis on Fatigue Fracture of the Flame-Quenched 8.8Al-Bronze by Ultrasonic Vibratory Cavitation Erosion

2006 ◽  
Vol 118 ◽  
pp. 463-468
Author(s):  
Sung Mo Hong ◽  
Min Ku Lee ◽  
G.H. Kim ◽  
Chang Kyu Rhee ◽  
K.H. Kim ◽  
...  
Keyword(s):  
Steady State ◽  
Incubation Period ◽  
Load Distribution ◽  
Cavitation Erosion ◽  
Impact Load ◽  
Fatigue Properties ◽  
Impact Loads ◽  
Cavitation Damage ◽  
Number Of Cycles ◽  
The Impact

In this study the fatigue properties due to cavitation damage of flame-quenched 8.8Al-bronze (8.8Al-4.5Ni-4.5Fe-Cu) as well as current nuclear pump materials (8.8Al-bronze, SUS316 and SR50A) have been investigated by using an ultrasonic vibratory cavitation test. For this the impact loads of cavitation bubbles generated by ultrasonic vibratory device quantitatively evaluated and simultaneously the cavitation erosion experiments have been carried out. The fatigue analysis on the cavitation damage of the materials has been made from the determined impact load distribution (e.g. impact load, bubble count) and erosion parameters (e.g. incubation period, MDPR). According to Miner’s law, the exponents b of the F-N relation (Fb N = Constant) at the incubation stage (N: the number of fracture cycle) were 5.62, 4.16, 6.25 and 8.1 for the 8.8Al-bronze, flame-quenched sample, SUS316 and SR50A alloys, respectively. At steady-state, the exponents b of the F-N curve (N: the number of cycles required for a 1μm increment of MDP) were determined as 6.32, 5, 7.14 and 7.76 for the 8.8Al-bronze, flame-quenched sample, SUS316 and SR50A alloys, respectively.

Numerical simulation of rock-breaking under the impact load of self-excited oscillating pulsed waterjet

2020 ◽  
Vol 96 ◽  
pp. 103179 ◽  
Author(s):  
Hongsheng Li ◽  
Songyong Liu ◽  
Jiguang Jia ◽  
Fengchao Wang ◽  
Chuwen Guo
Keyword(s):  
Numerical Simulation ◽  
Impact Load ◽  
Rock Breaking ◽  
The Impact ◽  
Pulsed Waterjet

scholarly journals Study on Compound Mode Crack Propagation Law of Semi Circular Arch Roadway Under Impact Load

2021 ◽  
Author(s):  
Chengxiao Li ◽  
Renshu Yang ◽  
Yuantong Zhang ◽  
Chen An
Keyword(s):  
Numerical Simulation ◽  
Crack Propagation ◽  
Mixed Mode ◽  
Impact Load ◽  
Central Axis ◽  
Mode I ◽  
Finite Element Software ◽  
Circular Arch ◽  
Propagation Law ◽  
The Impact

Abstract Various kinds of defects are usually contained in the underground roadway. When the roadway is impacted by external load, the location of defects will influence the roadway with different degrees. In order to study the effect of the location of defects on crack propagation in roadway, in this paper, the stress wave produced by the bullet impacting the incident rod was used as the impact load. Meanwhile, the variations of speed, displacement and dynamic stress intensity factor (DSIF) of cracks, during crack propagation, were obtained by using the experimental system of digital laser dynamic caustics (DLDC). And the extended finite element software ABAQUS is used for numerical simulation. Based on the method of experimental-numerical simulation, the crack propagation path is verified and the impact fracture behavior of semi-circular arch roadway with different defect positions is presented. It can be concluded that when the prefabricated crack is located at the central axis of sample, the crack propagation belongs to pure mode I; when the prefabricated crack is 5mm away from the central axis, the crack propagation appears between mode I and I-II mixed mode alternately; when the prefabricated crack is at the edge of semi-circular arch roadway, the crack propagation follows I-II mixed mode

scholarly journals Numerical simulation of cavitation characteristics in high speed water entry of head-jetting underwater vehicle

2021 ◽  
Vol 39 (4) ◽  
pp. 810-817
Author(s):  
Hairui Zhao ◽  
Yao Shi ◽  
Guang Pan
Keyword(s):  
Numerical Simulation ◽  
High Speed ◽  
Impact Load ◽  
Underwater Vehicle ◽  
Water Entry ◽  
Engineering Practice ◽  
Entry Angle ◽  
Air Jet ◽  
Entry Velocity ◽  
The Impact

Autonomous underwater vehicle will be subjected to a huge impact load during high speed water entry, which will damage the structure and the internal instruments of the vehicle. Therefore, it is of great significance to study the buffer mechanism of the vehicle during the process of water-entry. In this paper, a kind of head-jetting device with disk cavitation is used. The complex cavitation forms, under the three-phase coupling of gas, liquid and solid, in the water entry process of the vehicle on which the device is installed. In this paper, the numerical simulation of high-speed water entry of the vehicle equipped with head jet device is carried out. Through the analysis of water entry cavitation under typical working conditions, the following conclusions are obtained. After the installation of head jet device, the water entry cavity of the vehicle changes gradually from cone to spindle shape. The air jet, compared with that without jet, can promote the formation of water inlet supercavitation, decrease the interaction area between the vehicle and water, and reduce the impact load during water entry. At the same water entry depth, the diameter of cavitation increases with the amount of air jet. The water entry velocity has a great influence on the difference of cavitation shape. The water entry depth closure phenomenon, when the water entry velocity is less than 100 m/s, can be observed in the depth of 3.5 times of the projectile length. The water entry angle has a significant effect on the cavitation shape. The cavity shows obvious asymmetry when the vehicle slants into the water, and the diameter and length of the bubbles decrease with the increase of the water entry angle. The research content of this paper provides technical support for the engineering practice of high-speed water entry and load reduction, and the conclusions are of great significance in related fields.

Impact Load Buffering Method Based on Stress Wave Attenuation Principle

2019 ◽  
Vol 11 (02) ◽  
pp. 1950019 ◽  
Author(s):  
Lin Gan ◽  
He Zhang ◽  
Cheng Zhou ◽  
Lin Liu
Keyword(s):  
Stress Wave ◽  
Wave Attenuation ◽  
Impact Load ◽  
Dynamics Simulation ◽  
Scanning System ◽  
Isolation Method ◽  
Element Analysis ◽  
System A ◽  
High Emission ◽  
The Impact

Rotating scanning motor is the important component of synchronous scanning laser fuze. High emission overload environment in the conventional ammunition has a serious impact on the reliability of the motor. Based on the theory that the buffer pad can attenuate the impact stress wave, a new motor buffering Isolation Method is proposed. The dynamical model of the new buffering isolation structure is established by ANSYS infinite element analysis software to do the nonlinear impact dynamics simulation of rotating scanning motor. The effectiveness of Buffering Isolation using different materials is comparatively analyzed. Finally, the Macht hammer impact experiment is done, the results show that in the experience of the 70,000[Formula: see text]g impact acceleration, the new buffering Isolation method can reduce the impact load about 15 times, which can effectively alleviate the plastic deformation of rotational scanning motor and improve the reliability of synchronization scanning system. A new method and theoretical basis of anti-high overload research for Laser Fuze is presented.

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