Analysis and Inversion of Contact Stress for the Finite Thickness Neo-Hookean Layer

2018 ◽  
Vol 85 (10) ◽  
Author(s):  
Heng Yang ◽  
Xue-Feng Yao ◽  
Shen Wang ◽  
Yu-Chao Ke ◽  
Sheng-Hao Huang ◽  
...  
Keyword(s):  
Contact Stress ◽  
Contact Surface ◽  
Finite Thickness ◽  
Three Dimensional ◽  
Image Correlation ◽  
Rubber Layer ◽  
Inverse Approach ◽  
Element Simulation ◽  
Loading Modes ◽  
Nonlinear Finite Element Simulation

In this paper, the theoretical analysis and the inversion of the contact stress on the finite thickness rubber contact surface with the friction effect are investigated. First, an explicit expression of deformation and stress on the surface of rubber under a rigid spherical indenter is developed by means of theoretical model, dimensional analysis, and nonlinear finite element simulation. Second, the inverse approach for obtaining the contact stress on the finite thickness rubber contact surface is presented and verified theoretically. Also, the displacement, the stress field, and the friction coefficient are obtained by means of three-dimensional digital image correlation (3D DIC) method. Finally, the applicability to other hyperelastic models, general boundary conditions, and loading modes are discussed. The results will provide an important theoretical and experimental basis for evaluating the contact stress on the finite thickness rubber layer.

Analyzing the Contacting Stresses of Ball in Servo Disc Brake

2013 ◽  
Vol 419 ◽  
pp. 280-285
Author(s):  
Jin Yue Tian ◽  
Zheng Ning Ren ◽  
Jin Wei Wang ◽  
Jin Yu Yao ◽  
Shi Xin Lan ◽  
...  
Keyword(s):  
Stress Distribution ◽  
Theoretical Analysis ◽  
Contact Stress ◽  
Contact Surface ◽  
Optimization Design ◽  
Three Dimensional ◽  
Elastic Displacement ◽  
Disc Brake ◽  
Ball Bearings

The ball's stress distribution in tractor servo disc brake usually is three dimensional in tractor. In this article,the contact theoretical analysis is used to calculate the contact face action distribution between the saddle ball bearings, the elastic displacement, train and stress distributed situation was determined in contact surface. The results show that the method is completely feasible, this method was suitable similarly for the solution contact stress question, the data has provided the important reference for the contact face optimization design.

scholarly journals 3D Studies of Indentation by Combined X-Ray Tomography and Digital Volume Correlation

2013 ◽  
Vol 592-593 ◽  
pp. 14-21 ◽  
Author(s):  
Mahmoud Mostafavi ◽  
Yelena Vertyagina ◽  
Christina Reinhard ◽  
Robert Bradley ◽  
Xia Jiang ◽  
...  
Keyword(s):  
Crack Opening ◽  
Three Dimensional ◽  
Image Correlation ◽  
Digital Volume Correlation ◽  
Surface Characterisation ◽  
X Ray ◽  
Element Simulation ◽  
Potential Applications ◽  
Deformation Processes ◽  
X Ray Computed

Hardness testing obtains material properties from small specimens via measurement of load-displacement response to an imposed indentation; it is a surface characterisation technique so, except in optically transparent materials, there is no direct observation of the assumed damage and deformation processes within the material. Three-dimensional digital image correlation (digital volume correlation) is applied to study deformation beneath indentations, mapping the relative displacements between high-resolution synchrotron X-ray computed tomographs (0.9 μm voxel size). Two classes of material are examined: ductile aluminium-silicon carbide composite (Al-SiC) and brittle alumina (Al2O3). The measured displacements for Hertzian indentation in Al-SiC are in good agreement with an elastic-plastic finite element simulation. In alumina, radial cracking is observed beneath a Vickers indentation and the crack opening displacements are measured, in situ under load, for the first time. Potential applications are discussed of this characterization technique, which does not require resolution of microstructural features.

Finite Element Studies of Homogeneous and Heterogeneous Dislocation Nucleation based on the Rice-Peierls Framework

2011 ◽  
Vol 1363 ◽  
Author(s):  
T.L. Li ◽  
J.H. Lee ◽  
Y.F. Gao
Keyword(s):  
Finite Element ◽  
Finite Thickness ◽  
Three Dimensional ◽  
Crack Tip ◽  
Dislocation Core ◽  
Dislocation Nucleation ◽  
Small Scale ◽  
Direction Parallel ◽  
Element Simulation ◽  
Geometric Boundary

ABSTRACTThe study of dislocation nucleation has gained increasing attentions recently primarily due to the advancement of small scale mechanical testing methods. Based on the classic Rice model of dislocation nucleation from a crack tip in which the dislocation core is modeled by a continuous slip field, a nonlinear finite element method can be formulated with the interplanar potential as the input, and the development of interplanar slip field can be solved from the resulting boundary value problems. The effects of geometric boundary conditions, loading patterns, etc. can be conveniently determined, as opposed to the time consuming molecular simulations. To validate the method, we compare the simulations results of homogeneous dislocation nucleation and heterogeneous dislocation nucleation from a two-dimensional crack tip to the literature results. As proposed by Rice and Beltz (J. Mech. Phys. Solids, 1994), the activation energy for dislocation nucleation from a three-dimensional crack tip depends on the finite thickness in the direction parallel to the crack tip, which has been successfully reproduced in the finite element simulation results reported here.

scholarly journals Shear Capacity of Reinforced Concrete Beams under Monotonic and Cyclic Loads: Experiments and Computational Models

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4092
Author(s):  
Kamil Bacharz ◽  
Barbara Goszczyńska
Keyword(s):  
Reinforced Concrete ◽  
Laboratory Tests ◽  
Computational Models ◽  
Concrete Beams ◽  
Shear Capacity ◽  
Reinforced Concrete Beams ◽  
Image Correlation ◽  
Engineering Practice ◽  
Cyclic Loads ◽  
Loading Modes

The paper reports the results of a comparative analysis of the experimental shear capacity obtained from the tests of reinforced concrete beams with various static schemes, loading modes and programs, and the shear capacity calculated using selected models. Single-span and two-span reinforced concrete beams under monotonic and cyclic loads were considered in the analysis. The computational models were selected based on their application to engineering practice, i.e., the approaches implemented in the European and US provisions. Due to the changing strength characteristics of concrete, the analysis was also focused on concrete contribution in the shear capacity of reinforced concrete beams in the cracked phase and on the angle of inclination of diagonal struts. During the laboratory tests, a modern ARAMIS digital image correlation (DIC) system was used for tracking the formation and development of diagonal cracks.

Thermomechanical Coupling of a Hyper-viscoelastic Truck Tire and a Pavement Layer and its Impact on Three-dimensional Contact Stresses

2021 ◽  
pp. 036119812110171
Author(s):  
Angeli Jayme ◽  
Imad L. Al-Qadi
Keyword(s):  
Contact Stress ◽  
Contact Area ◽  
Three Dimensional ◽  
Interaction Model ◽  
Rolling Resistance ◽  
Contact Stresses ◽  
Thermomechanical Coupling ◽  
Temperature Profiles ◽  
Near Surface ◽  
Truck Tire

A thermomechanical coupling between a hyper-viscoelastic tire and a representative pavement layer was conducted to assess the effect of various temperature profiles on the mechanical behavior of a rolling truck tire. The two deformable bodies, namely the tire and pavement layer, were subjected to steady-state-uniform and non-uniform temperature profiles to identify the significance of considering temperature as a variable in contact-stress prediction. A myriad of ambient, internal air, and pavement-surface conditions were simulated, along with combinations of applied tire load, tire-inflation pressure, and traveling speed. Analogous to winter, the low temperature profiles induced a smaller tire-pavement contact area that resulted in stress localization. On the other hand, under high temperature conditions during the summer, higher tire deformation resulted in lower contact-stress magnitudes owing to an increase in the tire-pavement contact area. In both conditions, vertical and longitudinal contact stresses are impacted, while transverse contact stresses are relatively less affected. This behavior, however, may change under a non-free-rolling condition, such as braking, accelerating, and cornering. By incorporating temperature into the tire-pavement interaction model, changes in the magnitude and distribution of the three-dimensional contact stresses were manifested. This would have a direct implication on the rolling resistance and near-surface behavior of flexible pavements.

scholarly journals In-Process Measurement of Three-Dimensional Deformations Based on Speckle Photography

2021 ◽  
Vol 11 (11) ◽  
pp. 4981
Author(s):  
Andreas Tausendfreund ◽  
Dirk Stöbener ◽  
Andreas Fischer
Keyword(s):  
Evaluation Method ◽  
Process Analysis ◽  
Plane Deformation ◽  
Three Dimensional ◽  
Machining Process ◽  
Image Correlation ◽  
Speckle Photography ◽  
Process Measurement ◽  
Out Of Plane ◽  
Plane Deformations

In the concept of the process signature, the relationship between a material load and the modification remaining in the workpiece is used to better understand and optimize manufacturing processes. The basic prerequisite for this is to be able to measure the loads occurring during the machining process in the form of mechanical deformations. Speckle photography is suitable for this in-process measurement task and is already used in a variety of ways for in-plane deformation measurements. The shortcoming of this fast and robust measurement technique based on image correlation techniques is that out-of-plane deformations in the direction of the measurement system cannot be detected and increases the measurement error of in-plane deformations. In this paper, we investigate a method that infers local out-of-plane motions of the workpiece surface from the decorrelation of speckle patterns and is thus able to reconstruct three-dimensional deformation fields. The implementation of the evaluation method enables a fast reconstruction of 3D deformation fields, so that the in-process capability remains given. First measurements in a deep rolling process show that dynamic deformations underneath the die can be captured and demonstrate the suitability of the speckle method for manufacturing process analysis.

Sign in / Sign up

Export Citation Format

Share Document