Numerical Simulation of Frictional Heating Effects of Sliding Friction Bearings for Isolated Bridges

2018 ◽  
Vol 18 (08) ◽  
pp. 1840008
Author(s):  
Qiang Han ◽  
Jianian Wen ◽  
Zilan Zhong ◽  
Xiuli Du
Keyword(s):  
Energy Dissipation ◽  
Sliding Friction ◽  
Frictional Heating ◽  
Numerical Results ◽  
Effective Stiffness ◽  
Fe Model ◽  
Sliding Bearings ◽  
Heating Effects ◽  
Friction Pendulum ◽  
Friction Bearings

Sliding friction bearings are effective passive devices to mitigate the seismic responses of structures. Extensive researches have been conducted on sliding bearings. However, most previous studies were based on the assumption that the effects of frictional heating are negligible. A three-dimensional thermal-mechanical-coupled finite element (FE) model of the friction pendulum system (FPS) was developed in this study. Good agreements between the numerical results and the data measured in the previous tests, in terms of the force–displacement curves and temperature time-histories, indicate that the proposed FE model can predict the response of the FPS. Based on the developed FE model, the surface temperature distribution, the effective stiffness and the energy dissipation of the double concave friction pendulum and multiple friction pendulum bearings were investigated and compared. In addition, the thermal states of the sliding bearings in the bridge during earthquake were evaluated. The numerical results indicate that the temperature rise in the sliding bearings leads to the degradation of the effective stiffness and less energy dissipation. The relative displacements of the bearings increase considering the frictional heating effects in the bearings. If the frictional heating of the bearings is ignored, the peak bearing displacements will be underestimated.

scholarly journals Experimental and Numerical Analysis of the Mechanical Properties of a Pretreated Shape Memory Alloy Wire in a Self-Centering Steel Brace

Processes ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 80
Author(s):  
Bo Zhang ◽  
Sizhi Zeng ◽  
Fenghua Tang ◽  
Shujun Hu ◽  
Qiang Zhou ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Energy Dissipation ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Loading Rate ◽  
Effective Elastic Modulus ◽  
Maximum Energy ◽  
Numerical Results ◽  
Energy Dissipation Capacity

As a stimulus-sensitive material, the difference in composition, fabrication process, and influencing factors will have a great effect on the mechanical properties of a superelastic Ni-Ti shape memory alloy (SMA) wire, so the seismic performance of the self-centering steel brace with SMA wires may not be accurately obtained. In this paper, the cyclic tensile tests of a kind of SMA wire with a 1 mm diameter and special element composition were tested under multi-working conditions, which were pretreated by first tensioning to the 0.06 strain amplitude for 40 cycles, so the mechanical properties of the pretreated SMA wires can be simulated in detail. The accuracy of the numerical results with the improved model of Graesser’s theory was verified by a comparison to the experimental results. The experimental results show that the number of cycles has no significant effect on the mechanical properties of SMA wires after a certain number of cyclic tensile training. With the loading rate increasing, the pinch effect of the hysteresis curves will be enlarged, while the effective elastic modulus and slope of the transformation stresses in the process of loading and unloading are also increased, and the maximum energy dissipation capacity of the SMA wires appears at a loading rate of 0.675 mm/s. Moreover, with the initial strain increasing, the slope of the transformation stresses in the process of loading is increased, while the effective elastic modulus and slope of the transformation stresses in the process of unloading are decreased, and the maximum energy dissipation capacity appears at the initial strain of 0.0075. In addition, a good agreement between the test and numerical results is obtained by comparing with the hysteresis curves and energy dissipation values, so the numerical model is useful to predict the stress–strain relations at different stages. The test and numerical results will also provide a basis for the design of corresponding self-centering steel dampers.

scholarly journals Optimal Energy Dissipation in Sliding Friction Simulations

2012 ◽  
Vol 48 (1) ◽  
pp. 41-49 ◽  
Author(s):  
A. Benassi ◽  
A. Vanossi ◽  
G. E. Santoro ◽  
E. Tosatti
Keyword(s):  
Energy Dissipation ◽  
Sliding Friction ◽  
Optimal Energy

Influence of sliding bearing design on efficiency of the fluoroplast macromodifier for antifriction carbon plastics

2021 ◽  
pp. 65-75
Author(s):  
I. V. Lishevich ◽  
A. V. Anisimov ◽  
G. I. Nikolaev ◽  
A. S. Savelov ◽  
A. S. Sargsyan
Keyword(s):  
Sliding Friction ◽  
Friction Unit ◽  
Sliding Bearings ◽  
Friction Zone ◽  
Reinforced Plastics ◽  
Friction Units ◽  
Carbon Plastics ◽  
Key Factor ◽  
Fiber Reinforced Plastics ◽  
Bearing Design

The paper presents the results of laboratory and bench tests of UGET and FUT antifriction carbon plastics macro modified with PTFE. The efficiency (friction coefficient reduction) of this modification of carbon fiber reinforced plastics has been confirmed. The dependence of the method’s efficiency on the design of sliding friction units has been established. The plastic deformation of the fluoroplastic is the key factor that determines the effectiveness of the modifier when designing sliding bearings. The design of the friction unit should exclude the pressure gradient in the fluoroplastic protectors and prevent the possibility of an uncontrolled exit of the fluoroplastic from the friction zone.

Thermo-mechanical analysis of train wheel-rail contact using a novel finite-element model

2020 ◽  
Vol 72 (5) ◽  
pp. 687-693
Author(s):  
Liuqing Yang ◽  
Ming Hu ◽  
Deming Zhao ◽  
Jing Yang ◽  
Xun Zhou
Keyword(s):  
Finite Element ◽  
Peer Review ◽  
Frictional Heating ◽  
Element Model ◽  
Mechanical Analysis ◽  
Partial Slip ◽  
Computational Time ◽  
Fe Model ◽  
Content Type ◽  
Explicit Finite Element

Purpose The purpose of this paper is to develop a novel method for analyzing wheel-rail (W-R) contact using thermo-mechanical measurements and study the effects of heating on the characteristics of W-R contact under different creepages. Design/methodology/approach This study developed an implicit-explicit finite element (FE) model which could solve both partial slip and full sliding problems by setting different angular velocities on the wheels. Based on the model, four material types under six different creepages were simulated. Findings The results showed that frictional heating significantly affected the residual stress distribution under large creepage conditions. As creepage increased, the temperature of the wheel tread and rail head rose and the peak value was located at the trailing edge of the contact patch. Originality/value The proposed FE model could reduce computational time and thus cost to about one-third of the amount commonly found in previous literature. Compared to other studies, these results are in good agreement and offer a reasonable alternative method for analyzing W-R contact under various conditions. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-07-2019-0298

Nonlinear finite element analysis of smart laminated composite sandwich plates

2014 ◽  
Vol 14 (03) ◽  
pp. 1350075 ◽  
Author(s):  
S. K. Sarangi ◽  
B. Basa
Keyword(s):  
Finite Element ◽  
Fiber Composite ◽  
Orientation Angle ◽  
Shear Deformation Theory ◽  
Laminated Composite ◽  
Numerical Results ◽  
Sandwich Plates ◽  
Fe Model ◽  
Composite Sandwich ◽  
Composite Sandwich Plates

This paper deals with the nonlinear dynamic analysis of smart laminated composite sandwich plates. A three dimensional energy based finite element (FE) model has been developed for the composite sandwich plates integrated with the patches of active constrained layer damping (ACLD) treatment. Von Kármán type nonlinear strain–displacement relations and the first-order shear deformation theory (FSDT) are adopted individually for each layer of the sandwich plate in developing the FE model. The constraining layer of the ACLD treatment is considered to be made of active fiber composite (AFC) material. The Golla–Hughes–McTavish (GHM) method is used to model the constrained viscoelastic layer of the ACLD treatment in the time domain. Sandwich plates with symmetric and antisymmetric laminated faces separated by HEREX core are considered for evaluation of the numerical results. The numerical results indicate that the ACLD patches significantly improve the damping characteristics of the composite sandwich plates for suppressing their geometrically nonlinear transient vibrations. The effect of variation of piezoelectric fiber orientation angle in the AFC material on the control authority of the ACLD patches is also investigated.

scholarly journals Simulation of Tidal Energy Extraction, Using Fluent Model

2020 ◽  
Vol 160 ◽  
pp. 02002
Author(s):  
Hamidreza Alizadeh Hamedani
Keyword(s):  
Energy Dissipation ◽  
Water Surface ◽  
Tidal Flow ◽  
Free Water ◽  
Tidal Energy ◽  
Numerical Results ◽  
Energy Extraction ◽  
Flow Acceleration ◽  
Free Water Surface ◽  
Fluent Software

This study has been performed to develop our knowledge about marine sources energy extraction. Water in the channel has been simulated in laboratory scale by means of FLUENT software. The turbine tidal flow is generated by a moving disk which applies a pressure decrement with energy dissipation. Free water surface is estimated by means of fluid volume in the model which changes freely. The numerical results illustrate that eddy sequence has been generated after the tidal flow of turbine and a flow acceleration is generated nearby, especially beneath the energy extraction devise. Free water surface drop due to energy extraction is considered in model results that seems a to improve the turbine eddy sequence.

scholarly journals Seismic Behavior of Steel Column Base with Slip-Friction Connections

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 3986
Author(s):  
Chengyu Li ◽  
Qi Liu ◽  
Gongwen Li
Keyword(s):  
Free Energy ◽  
Energy Dissipation ◽  
Axial Compression ◽  
Sliding Friction ◽  
Future Research ◽  
Hysteretic Performance ◽  
Good Energy ◽  
Base Connections ◽  
The Cost ◽  
Column Base

Traditional rigid column base connections are damaged to different degrees after an earthquake and the damage is generally nonrecoverable. Thus, the cost of repairing or dismantling is quite high. A new type of slip-friction column base connection is proposed in this paper, which aims to replace the yielding energy dissipation of the traditional column base connection by the sliding friction energy dissipation between the arc endplates, thus achieving the design objective of damage-free energy dissipation. Finite element simulation was conducted to study the hysteretic performance of the proposed connections considering different axial compression ratios. The research indicates that both kinds of the proposed connections show good energy dissipation behavior and the increase of axial compression force can increase the energy dissipation ability. It also shows that the two kinds of connections can achieve the objective of damage-free energy dissipation. For the proposed connection, future research is still needed such as corresponding tests in the laboratory, the effect of the connection on the whole structure, and the re-centering systems for the connections.

scholarly journals Single-asperity sliding friction across the superconducting phase transition

2020 ◽  
Vol 6 (12) ◽  
pp. eaay0165 ◽  
Author(s):  
Wen Wang ◽  
Dirk Dietzel ◽  
André Schirmeisen
Keyword(s):  
Energy Dissipation ◽  
Sliding Friction ◽  
Point Contact ◽  
Electronic Energy ◽  
Contact Friction ◽  
Electron Systems ◽  
Single Asperity ◽  
Large Peak ◽  
Friction Models ◽  
Current Point

In sliding friction, different energy dissipation channels have been proposed, including phonon and electron systems, plastic deformation, and crack formation. However, how energy is coupled into these channels is debated, and especially, the relevance of electronic dissipation remains elusive. Here, we present friction experiments of a single-asperity sliding on a high-Tc superconductor from 40 to 300 kelvin. Overall, friction decreases with temperature as generally expected for nanoscale energy dissipation. However, we also find a large peak around Tc. We model these results by a superposition of phononic and electronic friction, where the electronic energy dissipation vanishes below Tc. In particular, we find that the electronic friction constitutes a constant offset above Tc, which vanishes below Tc with a power law in agreement with Bardeen-Cooper-Schrieffer theory. While current point contact friction models usually neglect such friction contributions, our study shows that electronic and phononic friction contributions can be of equal size.

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