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Contact area

About: Contact area is a research topic. Over the lifetime, 12358 publications have been published within this topic receiving 256401 citations. The topic is also known as: contact patch & contact region.


Papers
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Journal ArticleDOI
TL;DR: In this article, a semi-analytical method for the tridimensional elastic-plastic contact between two hemispherical asperities is proposed, which can be either load-driven or displacement-driven.
Abstract: A semi-analytical method for the tridimensional elastic-plastic contact between two hemispherical asperities is proposed. The first part of the paper describes the algorithm used to deal with the normal contact, which can be either load-driven or displacement-driven (dd). Both formulations use the conjugate gradient method and the discrete convolution and fast Fourier transform (DC-FFT) technique. A validation of the code is made in the case of the displacement-driven formulation for an elastic-plastic body in contact with a rigid punch, simulating a nano-indentation test. Another new feature is the treatment of the contact between two elastic-plastic bodies. The model is first validated through comparison with the finite element method. The contact pressure distribution, the hydrostatic pressure and the equivalent plastic strain state below the contacting surfaces are also found to be strongly modified in comparison to the case of an elastic-plastic body in contact with a purely elastic body. The way to consider rolling and sliding motion of the contacting bodies consists of solving the elastic-plastic contact at each time step while upgrading the geometries as well as the hardening state along the moving directions. The derivations concerning the interference calculation at each step of the sliding process are then shown, and an application to the tugging between two spherical asperities in simple sliding (dd formulation) is made. The way to project the forces in the global reference is outlined, considering the macro-projection due to the angle between the plane of contact and the sliding direction, and the micro-projection due to the pile-up induced by the permanent deformation of the bodies due to their relative motion. Finally, a load ratio is introduced and results are presented in terms of forces, displacements, and energy loss in the contact.

77 citations

Journal ArticleDOI
TL;DR: In this paper, the deformation of an elastic-plastic half-space by a rigid spherical indenter was examined with the finite element method, and the authors derived constitutive relations of the dimensionless mean contact pressure and contact area from finite element simulation results.

77 citations

Journal ArticleDOI
TL;DR: In this article, a new model based on support vector regression (SVR) technique is developed to calculate the force distribution instead of the FEM model, which can be used for real-time simulation of belt grinding.
Abstract: Industrial robots are recently introduced to the belt grinding of free-form surfaces to obtain high productive efficiency and constant surface quality. The simulation of belt grinding process can facilitate planning grinding paths and writing robotic programs before manufacturing. In simulation, it is crucial to get the force distribution in the contact area between the workpiece and the elastic contact wheel because the uneven distributed local forces are the main reason to the unequal local removals on the grated surface. The traditional way is to simplify this contact problem as a Signorini contact problem and use the finite element method (FEM) to calculate the force distribution. However, the FEM model is too computationally expensive to meet the real-time requirement. A new model based on support vector regression (SVR) technique is developed in this paper to calculate the force distribution instead of the FEM model. The new model approximates the FEM model with an error smaller than 5%, but executes much faster (1 s vs 15 min by FEM). With this new model, the real-time simulation and even the on-line robot control of grinding processes can be further conducted.

77 citations

Patent
08 Apr 1999
TL;DR: In this article, a lateral RF MOS device with a combined source connection structure is described. But the authors focus on the diffusion area and a conductive plug region, and do not discuss the connection between them.
Abstract: A lateral RF MOS device having a combined source connection structure is disclosed. The combined source connection structure utilizes a diffusion area and a conductive plug region. In one embodiment, the diffusion source area forms a contact region connecting the top surface of the semiconductor material to a highly conductive substrate of the lateral RF MOS transistor structure. In another embodiment, the diffusion source area is located completely within the epitaxial layer of the lateral RF MOS transistor structure. The conductive plug region makes a direct physical contact between a backside of the semiconductor material and the diffusion contact area.

76 citations

Journal ArticleDOI
TL;DR: Experimental data unambiguously reveal a stick-slip friction plateau above a critical scanning speed, in agreement with the thermally activated Prandtl-Tomlinson (PTT) model, but friction in experiments is larger than in simulations.
Abstract: Atomic force microscopy (AFM) and atomistic simulations of atomic friction with silicon oxide tips sliding on Au(111) are conducted at overlapping speeds. Experimental data unambiguously reveal a stick-slip friction plateau above a critical scanning speed, in agreement with the thermally activated Prandtl-Tomlinson (PTT) model. However, friction in experiments is larger than in simulations. PTT energetic parameters for the two are comparable, with minor differences attributable to the contact area's influence on the barrier to slip. Recognizing that the attempt frequency may be determined by thermal vibrations of the larger AFM tip mass or instrument noise fully resolves the discrepancy. Thus, atomic stick-slip is well described by the PTT model if sources of slip-assisting energy are accounted for.

76 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023102
2022253
2021375
2020467
2019554
2018528