scholarly journals Stiffness of Carpentry Connections – Numerical Modelling vs. Experimental Test

2015 ◽  
Vol 11 (2) ◽  
pp. 121-135
Author(s):  
Miloš Kekeliak ◽  
Jozef Gocál ◽  
Josef Vičan
Keyword(s):  
Surface Roughness ◽  
Numerical Model ◽  
Numerical Modelling ◽  
Contact Stiffness ◽  
Experimental Tests ◽  
Normal Contact ◽  
Study Results ◽  
Normal Contact Stiffness ◽  
Contact Surfaces ◽  
Mortise And Tenon

Abstract In this paper, numerical modelling of the traditional carpentry connection with mortise and tenon is presented. Numerical modelling is focused on its stiffness and the results are compared to results of experimental tests carried out by (Feio, 2005) [6]. To consider soft behaviour of wood in carpentry connections, which are related to its surface roughness and geometrical accuracy of the contact surfaces, the characteristics of the normal contact stiffness, determined experimentally, are introduced in the numerical model. Parametric study by means of numerical modelling with regard to the sensitivity of connection stiffness to contact stiffness is presented. Based on the study results, in conclusion there are presented relevant differences between the results of numerical modelling and experimental tests (Feio, 2005) [6].

scholarly journals Strength of the shaft/hub joint using a finite element model

2019 ◽  
pp. 9-18
Author(s):  
Manuel Salgado-Cruz ◽  
Claudia Cortés-García ◽  
Dariusz Slawomir Szwedowicz-Wasik ◽  
Eladio Martínez-Rayón
Keyword(s):  
Surface Roughness ◽  
Finite Element ◽  
Contact Stiffness ◽  
Load Capacity ◽  
Element Model ◽  
Numerical Results ◽  
Normal Contact ◽  
Interference Fit ◽  
Axial Load Capacity ◽  
Normal Contact Stiffness

This article describes the effect of the roughness size on the axial slip strength between the parts of shaft/hub joints with interference fit. The surface roughness was obtained from a turning process with different finishes (fine, medium and rough). A finite element modeling was developed, which uses a normal contact stiffness equivalent to the size of the surface roughness between the joint pieces to represent the real contact. In order to validate the numerical model, theoretical results of contactpressure and extraction force of the shaft/hub joint with smooth elements were compared with the corresponding numerical results obtained. The numerical results from studies that considered the size of the surface roughness showed that the axial load capacity of the joint decreased with larger roughness.

scholarly journals Linear relationship of normal and tangential contact stiffness with load

2020 ◽  
Vol 476 (2243) ◽  
pp. 20200329
Author(s):  
K. S. Parel ◽  
R. J. Paynter ◽  
D. Nowell
Keyword(s):  
Surface Roughness ◽  
Linear Relationship ◽  
Normal Load ◽  
Contact Stiffness ◽  
Roughness Parameter ◽  
Image Correlation ◽  
Tangential Load ◽  
Normal Contact ◽  
Tangential Contact ◽  
Normal Contact Stiffness

Measurements with digital image correlation of normal and tangential contact stiffness for ground Ti-6Al-4V interfaces suggest a linear relationship between normal contact stiffness and normal load and a linear relationship between tangential contact stiffness and tangential load. The normal contact stiffness is observed approximately to be inversely proportional to an equivalent surface roughness parameter, defined for two surfaces in contact. The ratio of the tangential contact stiffness to the normal contact stiffness at the start of tangential loading is seen to be given approximately by the Mindlin ratio. A simple empirical model is proposed to estimate both the normal and tangential contact stiffness at different loads for a ground Ti-6Al-4V interface, on the basis of the equivalent surface roughness and the coefficient of friction.

scholarly journals Estimation of the Normal Contact Stiffness for Frictional Interface in Sticking and Sliding Conditions

Lubricants ◽  
2019 ◽  
Vol 7 (7) ◽  
pp. 56 ◽  
Author(s):  
Davide Tonazzi ◽  
Francesco Massi ◽  
Mario Salipante ◽  
Laurent Baillet ◽  
Yves Berthier
Keyword(s):  
Complex Dynamics ◽  
Contact Stiffness ◽  
Experimental Tests ◽  
Normal Contact ◽  
Indirect Determination ◽  
Normal Contact Stiffness ◽  
Frictional Interface ◽  
Set Up ◽  
Contact Parameters

Modeling of frictional contact systems with high accuracy needs the knowledge of several contact parameters, which are mainly related to the local phenomena at the contact interfaces and affect the complex dynamics of mechanical systems in a prominent way. This work presents a newer approach for identifying reliable values of the normal contact stiffness between surfaces in contact, in both sliding and sticking conditions. The combination of experimental tests, on a dedicated set-up, with finite element modeling, allowed for an indirect determination of the normal contact stiffness. The stiffness was found to increase with increasing contact pressure and decreasing roughness, while the evolution of surface topography and third-body rheology affected the contact stiffness when sliding.

One Method for Estimating Normal Contact Stiffness with Ra and Adhesion Rate

2013 ◽  
Vol 734-737 ◽  
pp. 2443-2450
Author(s):  
Peng Wang ◽  
Tian Yun Li ◽  
Xiang Zhu ◽  
Guo Xiong Pan
Keyword(s):  
Surface Roughness ◽  
Vibration Isolation ◽  
Contact Stiffness ◽  
Low Noise ◽  
Normal Contact ◽  
Surface Machining ◽  
Fractal Parameters ◽  
Normal Contact Stiffness ◽  
Adhesion Rate ◽  
The Cost

Based on the fractal contact theory, the model about the relation between normal contact stiffness and material properties as well as fractal parameters is established. Then by making use of the relation between fractal parameters and surface roughness, a new method for estimating the normal contact stiffness is put forward. The numerical results indicate that the contact stiffness increases as surface roughness decreases or adhesion rate increases. When the adhesion rate is constant, contact stiffness changes a little whileRa≥6.3μm, but the change is relatively bigger whenRa≤6.3μm. Considering both the cost of surface machining and the influence of contact stiffness on the whole system, the surface roughness is suggested to beRa=6.3μm. The results provide theoretical supports for vibration isolation analysis with gaskets and the process of low-noise construction.

scholarly journals Normal contact stiffness model considering 3D surface topography and actual contact status

2021 ◽  
Vol 12 (1) ◽  
pp. 41-50
Author(s):  
Linbo Zhu ◽  
Jian Chen ◽  
Zaoxiao Zhang ◽  
Jun Hong
Keyword(s):  
Contact Stiffness ◽  
Experimental Tests ◽  
Theoretical Models ◽  
Asperity Contact ◽  
Normal Contact ◽  
Elastic Plastic ◽  
Stiffness Model ◽  
3D Surface Topography ◽  
Normal Contact Stiffness ◽  
Relationship Of

Abstract. A normal contact stiffness model considering 3D topography and elastic–plastic contact of rough surfaces is presented in this paper. The asperities are generated from the measured surfaces using the watershed segmentation and a modified nine-point rectangle. The topography parameters, including the asperity locations, heights, and radii of the summit, are obtained. Asperity shoulder–shoulder contact is considered. The relationship of the contact parameters, such as the contact force, the deformation, and the mean separation of two surfaces, is modelled in the three different contact regimes, namely elastic, elastic–plastic and fully plastic. The asperity contact state is determined, and if the contact occurs, the stiffness of the single asperity pair is calculated and summed as the total normal stiffness of two contact surfaces. The developed model is validated using experimental tests conducted on two types of specimens and is compared with published theoretical models.

Normal Contact Stiffness Fractal Geometric Model Based on the Gamma Distribution of Rough Joint Surface

2013 ◽  
Vol 760-762 ◽  
pp. 2064-2067 ◽  
Author(s):  
Jing Fang Shen ◽  
Ke Xiang Wu ◽  
Fei Yang
Keyword(s):  
Convex Body ◽  
Gamma Distribution ◽  
Contact Stiffness ◽  
Geometric Model ◽  
Fractal Theory ◽  
Fractal Model ◽  
Joint Surface ◽  
Engineering Practice ◽  
Normal Contact ◽  
Normal Contact Stiffness

In this article, according to WenShuHua and Zhangxueniang fractal model, we point out the deficiency. Based on the fractal theory and Zhang, Wens contact stiffness fractal model, this paper puts forward Gamma distribution of rough joint surface normal contact stiffness. This paper considers micro convex body for ellipsoid, contact area for elliptic. This is slightly convex body for sphere hypothesis is more close to the actual situation. At the same time by using statistics theory, considering the contact ellipse long, short axis a and b are greater than zero, the assumption of a and b to two-dimensional Gamma distribution, it is more suitable for engineering practice.

Analysis and Research on Fractal Model of Normal Contact Stiffness of Joint Interfaces

2011 ◽  
Vol 328-330 ◽  
pp. 336-345
Author(s):  
Guo Sheng Lan ◽  
Xue Liang Zhang ◽  
Hong Qin Ding ◽  
Shu Hua Wen ◽  
Zhong Yang Zhang
Keyword(s):  
Numerical Simulation ◽  
Fractal Dimension ◽  
Normal Load ◽  
Contact Stiffness ◽  
Fractal Model ◽  
Normal Contact ◽  
Fractal Models ◽  
Normal Contact Stiffness

Through the analysis and research on three fractal models of normal contact stiffness of joint interfaces, the differences between them can be found. Furthermore, numerical simulation was carried out to obtain the complicated nonlinear relations between normal contact stiffness and the normal load. The results show that the normal contact stiffness increases with the normal load, decreases with G but complicatedly varies with D. According to different fractal dimension, we can chose an appropriate one among the three fractal models of normal contact stiffness of joint interfaces when describing normal contact stiffness of joint interfaces.

Sign in / Sign up

Export Citation Format

Share Document