Reaction force calculation for planetary sampling devices based on the predicted zone of influence

The method, which obtains a static-dynamic comprehensive effect from superposing static and dynamic effects, is inapplicable to large deformation and nonlinear elastic problems under strong earthquake action. The static and dynamic effects must be analyzed in a unified way. These effects involve a static-dynamic boundary transformation problem or a static-dynamic boundary unified problem. The static-dynamic boundary conversion method is tedious. If the node restraint reaction force caused by a static boundary condition is not applied, then the model is not balanced at zero moment, and the calculation result is distorted. The static numerical solution error is large when the structure possesses tangential static force in a viscoelastic static-dynamic unified boundary. This paper proposed a new static-dynamic unified artificial boundary based on an infinite element in ABAQUS to solve static-dynamic synthesis effects conveniently and accurately. The static and dynamic mapping theories of infinite elements were introduced. The characteristic of the infinite element, which has zero displacement at faraway infinity, was discussed in theory. The equivalent nodal force calculation formula of infinite element unified boundary was deduced from an external wave input. A calculation and application program of equivalent nodal forces was developed using the Python language to complete external wave inputting. This new method does not require a static and dynamic boundary transformation and import of stress field and constraint counterforce of boundary nodes. The static calculation precision of the infinite element unified boundary is more improved than the viscoelastic static-dynamic unified boundary, especially when the static load is in the tangential direction. In addition, the foundation simulation range of finite field can be significantly reduced given the utilization of the infinite element static dynamic unified boundary. The preciseness of static calculation and dynamic calculation and static-dynamic comprehensive analysis are unaffected.

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Dynamic analysis of a ten-link tooth-lever differential transmission

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/939/1/012024 ◽

2021 ◽

Vol 939 (1) ◽

pp. 012024

Author(s):

A Abdukarimov ◽

I Saidakulov

Keyword(s):

High Speed ◽

Reaction Force ◽

Transmission Mechanism ◽

Force Analysis ◽

Axis Of Rotation ◽

Processed Material ◽

Differential Transmission ◽

External Forces ◽

Force Calculation ◽

Force Characteristics

Abstract This article discusses the dynamics of a ten-link tooth-lever differential transmission mechanism. The force analysis of the transmission mechanism is given in order to find the dependence for determining the reaction in kinematic pairs and the balancing moment of the pair of forces and to show some features of the tooth-lever transmission mechanism. The force calculation was carried out taking into account the accelerated movement of links since their acceleration in modern high-speed machines is very significant. To obtain a more accurate concept of the external forces and moments loading the transmission mechanism in the accelerated movement of the links, the dynamics of the transient process of roller technological machines was considered. Cases of feeding the processed material were considered both from the side of the intermediate gears and from the side opposite to the parasitic gears. Dependencies were obtained to determine the force characteristics of this mechanism. Cases of pressure unloading and overloading on the processed material from the side of the free shaft, depending on the location of the transmission mechanism are shown. The dependence of the reaction force of intermediate gears on their own axes of rotation on the angle between the levers is shown. With an increase in the angle between the levers, the reaction of the intermediate gears on the axis of rotation increases.

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Development of a Knee Joint CT-FEM Model in Load Response of the Stance Phase During Walking Using Muscle Exertion, Motion Analysis, and Ground Reaction Force Data

Medicina ◽

10.3390/medicina56020056 ◽

2020 ◽

Vol 56 (2) ◽

pp. 56

Author(s):

Kunihiro Watanabe ◽

Hirotaka Mutsuzaki ◽

Takashi Fukaya ◽

Toshiyuki Aoyama ◽

Syuichi Nakajima ◽

...

Keyword(s):

Finite Element ◽

Knee Joint ◽

Ground Reaction Force ◽

Reaction Force ◽

Equivalent Stress ◽

Element Model ◽

Calculation Model ◽

Quantitative Ct ◽

Load Response ◽

Force Calculation

Background and objectives: There are no reports on articular stress distribution during walking based on any computed tomography (CT)-finite element model (CT-FEM). This study aimed to develop a calculation model of the load response (LR) phase, the most burdensome phase on the knee, during walking using the finite element method of quantitative CT images. Materials and Methods: The right knee of a 43-year-old man who had no history of osteoarthritis or surgeries of the knee was examined. An image of the knee was obtained using CT and the extension position image was converted to the flexion angle image in the LR phase. The bone was composed of heterogeneous materials. The ligaments were made of truss elements; therefore, they do not generate strain during expansion or contraction and do not affect the reaction force or pressure. The construction of the knee joint included material properties of the ligament, cartilage, and meniscus. The extensor and flexor muscles were calculated and set as the muscle exercise tension around the knee joint. Ground reaction force was vertically applied to suppress the rotation of the knee, and the thigh was restrained. Results: An FEM was constructed using a motion analyzer, floor reaction force meter, and muscle tractive force calculation. In a normal knee, the equivalent stress and joint contact reaction force in the LR phase were distributed over a wide area on the inner upper surface of the femur and tibia. Conclusions: We developed a calculation model in the LR phase of the knee joint during walking using a CT-FEM. Methods to evaluate the heteromorphic risk, mechanisms of transformation, prevention of knee osteoarthritis, and treatment may be developed using this model.

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Analysis of Dynamic Characteristics of Pile-Soil Coupling Effect in Consideration of Large Span Cable-Stayed Bridge

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.501-504.1270 ◽

2014 ◽

Vol 501-504 ◽

pp. 1270-1273

Author(s):

Wen Yuan Chen

Keyword(s):

Axial Force ◽

Soil Structure ◽

Coupling Effect ◽

Reaction Force ◽

Bending Moment ◽

Internal Force ◽

Cable Stayed Bridge ◽

Long Span ◽

Pile Cap ◽

Force Calculation

Using the viscouselastic artificial boundary, three conditions of long-span cable-stayed bridge are analyzed,such as pile cap consolidation, pile - structure and pile soil structure interaction. Natural frequency of bridge of pile - soil - structure coupling becomes small and cycle becomes long. The pile bottom reaction force decreased obviously, at the same time, the axial force , bending moment, axial force of cable, tower of axial force and bending moment is also reduced significantly. Cable-stayed bridge is a special flexible structure, so, static internal force calculation in the tower bottom consolidation pattern is safe, but the value is too large.

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Calculation of the Influence Zone for Planetary Sampling Based on DEM Simulation

International Journal of Aerospace Engineering ◽

10.1155/2021/6652273 ◽

2021 ◽

Vol 2021 ◽

pp. 1-11

Author(s):

Qian Li ◽

Junping Li ◽

Lanlan Xie

Keyword(s):

Soil Mechanics ◽

Reaction Force ◽

Lunar Soil ◽

Sampling Device ◽

Influence Zone ◽

Dem Simulation ◽

Related Research ◽

Physical Experiments ◽

Device Structures ◽

Force Calculation

In the design of planetary sampling devices, calculating the reaction force acting on the sampling devices is crucial. According to related research, the influence zone caused by sampling plays an important role in calculating the reaction force. A new method for estimating the range of the influence zone based on 3D DEM simulation is discussed in this paper. Taking lunar soil as an example, first, via validation of physical experiments, the DEM lunar soil simulant was proven to have mechanical properties similar to those of real lunar soil. Second, stress was selected as an indicator to identify the influence zone by computing the match percentage via a comparison between classical soil mechanics and DEM simulation. Using the proposed calculation method, it can be observed that the trend of change of influence zone at different sampling moments showed similar to the change of reaction force. Calculation of the influence zone can be used to analyze the reaction force of different gravity environments, sampling device structures, and motions.

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Application of Three-Moment Equation in Rudder Stock's Force Calculation

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.347-350.3435 ◽

2013 ◽

Vol 347-350 ◽

pp. 3435-3439

Author(s):

Bin Can Zhang

Keyword(s):

Mechanical Model ◽

Reaction Force ◽

Bending Moment ◽

Moment Equation ◽

Strength Theory ◽

Check Calculation ◽

Conventional Methods ◽

Force Calculation

The mechanical model of the rudder stock is established. The rudder stock can be simplified into a statically indeterminate beam. The reaction force from the support, torque and bending moment within the length of the rudder stock can be solved using three-moment equation. The stress in the profile of the stock is checked using the fourth strength theory. The calculation is directly carried out based on Ship Specification of Classification and Shipbuilding. Compared with the conventional methods, the results show that three-moment equation is correct and available in check calculation.

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Radiation-reaction force on a moving mirror

Journal de Physique I ◽

10.1051/jp1:1993237 ◽

1993 ◽

Vol 3 (11) ◽

pp. 2151-2159 ◽

Cited By ~ 10

Author(s):

Claudia Eberlein

Keyword(s):

Reaction Force ◽

Radiation Reaction ◽

Radiation Reaction Force

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Engineering-Geological Studies Of The Territory, Soils Of Foundation And Foundations Of The Architectural Monument Of The "Melnikov’s House" In Moscow

Promyshlennoe i Grazhdanskoe Stroitel stvo ◽

10.33622/0869-7019.2019.05.41-51 ◽

2019 ◽

pp. 41-51

Keyword(s):

Working Condition ◽

Overlying Water ◽

North East ◽

The North ◽

Geological Processes ◽

Architectural Monument ◽

Geological Conditions ◽

Zone Of Influence ◽

Complex Engineering ◽

Building Engineering

On the basis of engineering and design surveys of the building, engineering-geological and geophysical studies of the soils of the territory conducted by the article authors, as well as with due regard for the results of studies conducted on this territory by other authors, the features of the foundations, soils of their foundation and engineering-geological conditions of the territory of the Melnikov House are established. It is shown that the Melnikov house is located under complex engineering-geological conditions on the territory of high geological risk, in the zone of influence of tectonic disturbance. To the North of the area there is a zone of intersection of the observed disturbance with a larger disturbance that can have an impact on geological processes. To the North-East of the site of the Melnikov House, a sharp immersion of the roof of carbon deposits was revealed. It promotes groundwater seepage into limestone of the carbonate strata from overlying water-bearing sands and activation of processes of suffusion removal and sinkhole phenomena of the soil. The surveyed area is assessed as potentially karst-hazardous and adjacent to it from the North-East territory as karst-dangerous. In this regard any construction on the adjacent territory can provoke activation of sinkhole phenomena on the surface. The foundations of the building are basically in working condition. Existing defects can be eliminated during repair. The foundation soils mainly have sufficient bearing capacity. Areas of the base with bulk soil can be reinforced. However, when developing a project for the reconstruction of the building and its territory, it should be taken into account that the design of the Melnikov House does not provide for its operation on the loads at the formation of sinkholes.

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