Effects of Mechanical Flexibility and Clearance Size on the Wear at Revolute Joint in the Flexible Multibody Systems

2014 ◽  
Author(s):  
Bo Zhao ◽  
Xudong Dai ◽  
Shihao Wu
Keyword(s):  
Contact Force ◽  
Numerical Approach ◽  
Friction Model ◽  
Force Model ◽  
Wear Prediction ◽  
Normal Contact ◽  
Continuous Contact ◽  
Clearance Joint ◽  
Flexible Multibody ◽  
Flexible Component

By integrating the procedures of wear prediction with multibody dynamics, this paper proposed a numerical approach for the modeling and prediction of wear at revolute clearance joint in flexible multibody mechanical systems. In the approach, the flexible component was modeled by using absolute nodal coordinate formulation (ANCF)-based element. The clearance joint was modeled as a dry contact pair, in which the continuous contact force model proposed by Lankanrani and Nikravesh was applied to evaluate the normal contact force, and the friction effect was considered using the LuGre friction model. The calculation of wear was performed by an iterative wear prediction procedure based on Archard’s wear model. Using this approach, a planar slider-crank mechanism including a flexible rod and clearance joint was numerically investigated as a demonstrative example. Furthermore, the effects of the flexibility of the mechanism and the clearance size on the wear at clearance joint were also studied.

Modeling and prediction of wear at revolute clearance joints in flexible multibody systems

2013 ◽  
Vol 228 (2) ◽  
pp. 317-329 ◽  
Author(s):  
Bo Zhao ◽  
Zhi-Nan Zhang ◽  
Xu-Dong Dai
Keyword(s):  
Contact Force ◽  
Multibody Systems ◽  
Flexible Multibody Systems ◽  
Force Model ◽  
Wear Prediction ◽  
Clearance Joints ◽  
Modeling And Prediction ◽  
Clearance Joint ◽  
Flexible Multibody ◽  
Flexible Component

This article proposes a numerical approach for the modeling and prediction of wear at revolute clearance joints in flexible multibody systems by integrating the procedures of wear prediction with multibody dynamics. In the approach, the flexible component is modeled based on the absolute nodal coordinate formulation. The contact force in the clearance joint is applied using the continuous contact force model proposed by Lankanrani and Nikravesh and the friction effect is considered using the LuGre friction model. The simulation of wear is performed by an iterative wear prediction procedure based on Archard’s wear model. The radial basis function neural network technique is employed to deal with the pin-on-disc experimental data for obtaining the wear coefficient used in the wear prediction procedure at different contact conditions. The comparison of the wear predicted at the clearance joint in the rigid and flexible planar slider-crank mechanisms demonstrates that the proposed approach can be used to model and predict wear at revolute clearance joints in flexible multibody systems, and the wear result predicted is slightly reduced after taking the flexibility of components into account.

Dynamics Analysis of Truss Deployment Mechanism With Imperfect Joint Considering Input Fluctuation

2020 ◽  
Author(s):  
Zhengfeng Bai ◽  
Jijun Zhao ◽  
Xin Shi
Keyword(s):  
Contact Force ◽  
Dynamic Performance ◽  
Mathematic Model ◽  
Friction Model ◽  
Dynamic Responses ◽  
Force Model ◽  
Normal Contact ◽  
Clearance Joint ◽  
Contact Force Model ◽  
Dynamic Performance Analysis

Abstract Modern spacecraft usually has large deployment structure, which consisting of plenty of joints could produce undesirable dynamic responses when considering clearances in joints and driving input fluctuation. However, in the dynamic performance analysis of space deployment mechanism, the clearances and input fluctuation are always ignored. In this study, the dynamic responses of a flexible planar scissor-like truss deployment mechanism with imperfect joint considering clearance and input fluctuation are investigated using computational methodology. First, the mathematic model of clearance joint is established. The revolute clearance joint is considered as force constraint and the joint components of an imperfect joint with clearance are modeled as contact bodies. The normal contact force model of clearance joint is established using a continuous contact force model considering energy loss. The friction effect is considered using a modified Coulomb friction model. Then, the dynamics performances of the flexible planar scissor-like truss deployment mechanism with imperfect joint considering clearance and input fluctuation are presented and discussed. Different case studies for the scissor-like truss deployment mechanism with clearance are investigated considering driving input fluctuation. The simulation results show that the dynamic characteristics of the mechanism with clearance joint are changed more obviously when considering driving input fluctuation. Therefore, investigation implies that dynamics responses of the truss deployment mechanism are much worse when considering clearance joint and input fluctuation, which indicates that driving input fluctuation leads to more obvious degradation of the dynamic performance of the truss deployment mechanism with imperfect joint.

scholarly journals Dynamics of Multibody Systems With Spherical Clearance Joints

2005 ◽  
Author(s):  
P. Flores ◽  
J. Ambro´sio ◽  
J. C. P. Claro ◽  
H. M. Lankarani
Keyword(s):  
Contact Force ◽  
Multibody Systems ◽  
Contact Forces ◽  
Force Model ◽  
Clearance Joints ◽  
Continuous Contact ◽  
Clearance Joint ◽  
Contact Force Model ◽  
Dynamics Of Multibody Systems ◽  
The Impact

This work deals with a methodology to assess the influence of the spherical clearance joints in spatial multibody systems. The methodology is based on the Cartesian coordinates, being the dynamics of the joint elements modeled as impacting bodies and controlled by contact forces. The impacts and contacts are described by a continuous contact force model that accounts for geometric and mechanical characteristics of the contacting surfaces. The contact force is evaluated as function of the elastic pseudo-penetration between the impacting bodies, coupled with a nonlinear viscous-elastic factor representing the energy dissipation during the impact process. A spatial four bar mechanism is used as an illustrative example and some numerical results are presented, being the efficiency of the developed methodology discussed in the process of their presentation. The results obtained show that the inclusion of clearance joints in the modelization of spatial multibody systems significantly influences the prediction of components’ position and drastically increases the peaks in acceleration and reaction moments at the joints. Moreover, the system’s response clearly tends to be nonperiodic when a clearance joint is included in the simulation.

scholarly journals Dynamic Response of Multibody Systems with Multiple Clearance Joints

2012 ◽  
Vol 7 (3) ◽  
Author(s):  
Paulo Flores ◽  
Hamid M. Lankarani
Keyword(s):  
Contact Force ◽  
Multibody Systems ◽  
Equations Of Motion ◽  
Physical And Mechanical Properties ◽  
Contact Forces ◽  
Force Model ◽  
Normal Contact ◽  
Clearance Joints ◽  
Continuous Contact ◽  
Dissipative Term

A general methodology for the dynamic modeling and analysis of planar multibody systems with multiple clearance joints is presented. The inter-connecting bodies that constitute a real physical mechanical joint are modeled as colliding components, whose dynamic behavior is influenced by the geometric, physical and mechanical properties of the contacting surfaces. A continuous contact force model, based on the elastic Hertz theory, together with a dissipative term associated with the internal damping, is utilized to evaluate the intra-joint normal contact forces. The incorporation of the friction phenomenon, based on the classical Coulomb’s friction law, is also included in this study. The suitable contact force models are embedded into the dynamic equations of motion for the multibody systems. In the sequel of this process, the fundamental methods to deal with contact-impact events in mechanical systems are presented. Finally, two planar mechanisms with multiple revolute clearance joints are used to demonstrate the accuracy and efficiency of the presented approach and to discuss the main assumptions and procedures adopted. The effects of single versus multiple clearance revolute joints are discussed.

Nonlinear dynamic characteristics and control of planar linear array deployable structures consisting of scissor-like elements with revolute clearance joint

2020 ◽  
pp. 136943322097172
Author(s):  
Bo Li ◽  
San-Min Wang ◽  
Charis J Gantes ◽  
U-Xuan Tan
Keyword(s):  
Friction Coefficient ◽  
Contact Force ◽  
Initial Conditions ◽  
Equations Of Motion ◽  
Force Model ◽  
Deployable Structures ◽  
Clearance Joints ◽  
Continuous Contact ◽  
Clearance Joint ◽  
Parametric Effects

This paper comprehensively deals with the parametric effects of the joint clearance and friction coefficient on the dynamics of planar deployable structures consisting of scissor-like elements (SLEs). The dynamic model for scissor deployable structure is based on a comprehensive consideration of the symmetry and array characteristics of this mechanism and on a Lagrange method, which represents the motion equations. A modified nonlinear contact-force model is employed to evaluate the intrajoint contact force, and the incorporation of the friction effect between the inter-connecting bodies is included in this study. The total impact forces produced in the real mechanical joint are embedded into the dynamics and the differential equations of motion are solved numerically based on a set of initial conditions. The clearance size, angle velocity, and friction coefficient are analyzed and discussed separately. Using Poincaré map, the regular and irregular responses of the deployable mulitibody systems are observed. Next, a control scheme is evaluated to maintain a more stable behavior and continuous contact between the clearance joints. The controlled results are compared with those without control, concluding that some undesired effects caused by the clearance joints can be prevented or reduced, resulting in continuous contact at the clearance joint.

scholarly journals Dynamics of Multibody Systems With Spherical Clearance Joints

2006 ◽  
Vol 1 (3) ◽  
pp. 240-247 ◽  
Author(s):  
P. Flores ◽  
J. Ambrósio ◽  
J. C. P. Claro ◽  
H. M. Lankarani
Keyword(s):  
Contact Force ◽  
Multibody Systems ◽  
Contact Forces ◽  
Force Model ◽  
Clearance Joints ◽  
Continuous Contact ◽  
Clearance Joint ◽  
Contact Force Model ◽  
Dynamics Of Multibody Systems ◽  
The Impact

This work deals with a methodology to assess the influence of the spherical clearance joints in spatial multibody systems. The methodology is based on the Cartesian coordinates, with the dynamics of the joint elements modeled as impacting bodies and controlled by contact forces. The impacts and contacts are described by a continuous contact force model that accounts for geometric and mechanical characteristics of the contacting surfaces. The contact force is evaluated as function of the elastic pseudo-penetration between the impacting bodies, coupled with a nonlinear viscous-elastic factor representing the energy dissipation during the impact process. A spatial four-bar mechanism is used as an illustrative example and some numerical results are presented, with the efficiency of the developed methodology discussed in the process of their presentation. The results obtained show that the inclusion of clearance joints in the modelization of spatial multibody systems significantly influences the prediction of components’ position and drastically increases the peaks in acceleration and reaction moments at the joints. Moreover, the system’s response clearly tends to be nonperiodic when a clearance joint is included in the simulation.

scholarly journals Investigation on Dynamics of Mechanical System with Clearance Joint

2014 ◽  
Vol 8 (1) ◽  
pp. 224-229
Author(s):  
Zheng-Feng Bai ◽  
Bin-jiu Yang ◽  
Yi Sun
Keyword(s):  
Mechanical System ◽  
Frequency Domain Analysis ◽  
Friction Model ◽  
Dynamic Responses ◽  
Force Model ◽  
Clearance Joints ◽  
Continuous Contact ◽  
Clearance Joint ◽  
Joint Contact ◽  
Coulomb Friction Model

In this work, the dynamic responses and vibration characteristics of mechanical system with revolute clearance joints are investigated numerically. Considering clearance in joint, the intra-joint contact model that is generated at clearance joints is established using a nonlinear continuous contact force model and the friction effect is considered by using a modified Coulomb friction model. A well-known slider-crank mechanism with a revolute clearance joint is utilized to perform the investigation. The effects of clearance on dynamics of mechanical system are analyzed by timedomain responses and frequency domain analysis. The investigation results show that the dynamic responses of mechanical system with clearance are obviously vibration and the amplitude increases from the mechanism without clearance. The results also indicate that the behavior of mechanism with clearance is nonlinear.

Experimental Validation of a Volumetric Planetary Rover Wheel/Soil Interaction Model

2013 ◽  
Author(s):  
Willem Petersen ◽  
John McPhee
Keyword(s):  
Contact Force ◽  
Interaction Model ◽  
Contact Model ◽  
Soil Parameters ◽  
Model Parameters ◽  
Force Model ◽  
Normal Contact ◽  
Planetary Rover ◽  
Normal Contact Force ◽  
Contact Force Model

For the multibody simulation of planetary rover operations, a wheel-soil contact model is necessary to represent the forces and moments between the tire and the soft soil. A novel nonlinear contact modelling approach based on the properties of the hypervolume of interpenetration is validated in this paper. This normal contact force model is based on the Winkler foundation model with nonlinear spring properties. To fully define the proposed normal contact force model for this application, seven parameters are required. Besides the geometry parameters that can be easily measured, three soil parameters representing the hyperelastic and plastic properties of the soil have to be identified. Since it is very difficult to directly measure the latter set of soil parameters, they are identified by comparing computer simulations with experimental results of drawbar pull tests performed under different slip conditions on the Juno rover of the Canadian Space Agency (CSA). A multibody dynamics model of the Juno rover including the new wheel/soil interaction model was developed and simulated in MapleSim. To identify the wheel/soil contact model parameters, the cost function of the model residuals of the kinematic data is minimized. The volumetric contact model is then tested by using the identified contact model parameters in a forward dynamics simulation of the rover on an irregular 3-dimensional terrain and compared against experiments.

scholarly journals Chaos phenomenon and stability analysis of RU-RPR parallel mechanism with clearance and friction

2018 ◽  
Vol 10 (1) ◽  
pp. 168781401774625 ◽  
Author(s):  
Yulei Hou ◽  
Yi Wang ◽  
Guoning Jing ◽  
Yunjiao Deng ◽  
Daxing Zeng ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Contact Force ◽  
Parallel Mechanism ◽  
Degrees Of Freedom ◽  
Force Model ◽  
Obvious Effect ◽  
Normal Contact ◽  
Rotational Degrees Of Freedom ◽  
The Stability ◽  
Baumgarte Stabilization

The chaos phenomenon often exists in the dynamics system of the mechanism with clearance and friction, which has obvious effect on the stability of the mechanism, then it is worthy of attention for identifying the relationship between the friction coefficient and the stability of the mechanism. Two rotational degrees of freedom decoupled parallel mechanism RU-RPR is taken as the research object. Considering the clearance existing in the revolute pair, Lankarani–Nikravesh contact force model is used to calculate the normal contact force, and the Coulomb friction force model is used to calculate the tangential contact force. The dynamics model is established using Newton–Euler equations, and the Baumgarte stabilization method is used to keep the stability of the numerical analysis. Then, the equations are solved using the fourth adaptive Runge–Kutta method, and the effect of the revolute pair’s clearance on the dynamic behavior is analyzed. Poincare mapping is plotted, and the bifurcation diagrams are analyzed with varying the friction coefficient corresponding to different values of clearance size. The research contents possess a certain theoretical guidance significance and practical application value on the analysis of the chaotic motion and its stability in the dynamics of the parallel mechanism.

A continuous contact force model for impact analysis

2022 ◽  
Vol 168 ◽  
pp. 108739
Author(s):  
Jie Zhang ◽  
Xu Liang ◽  
Zhonghai Zhang ◽  
Guanhua Feng ◽  
Quanliang Zhao ◽  
...  
Keyword(s):  
Contact Force ◽  
Impact Analysis ◽  
Force Model ◽  
Continuous Contact ◽  
Contact Force Model
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