Contact interaction between a shell of revolution and rigid bodies with large deformations

1988 ◽  
Vol 20 (3) ◽  
pp. 398-403
Author(s):  
V. G. Bazhenov ◽  
V. K. Lomunov ◽  
G. V. Sheronov
Keyword(s):  
Contact Interaction ◽  
Large Deformations ◽  
Rigid Bodies ◽  
Shell Of Revolution

Design, Development and Preliminary Assessment of Grasping Devices for Robotized Medical Applications

2012 ◽  
Author(s):  
Olivier Piccin ◽  
Nitish Kumar ◽  
Laurence Meylheuc ◽  
Laurent Barbé ◽  
Bernard Bayle
Keyword(s):  
Large Deformations ◽  
Compliant Mechanism ◽  
Fem Analysis ◽  
Rigid Bodies ◽  
Medical Applications ◽  
Design Development ◽  
Preliminary Assessment ◽  
Service Capability ◽  
Compliant Parts ◽  
Medical Needle

This paper presents the development of NGDs (needle grasping devices) capable of handling elongated objects such as surgical needles. After describing the main demands of medical needle-based procedures, a requirement list for a typical NGD is presented. Some solution principles for a grasping device are generated, combined and then classified to obtain a set of principle variant solutions. The design study of some of these variant solutions is then developed and a discussion on two device candidates constructed using either interconnected rigid bodies or compliant parts will be presented. The mechanical behavior of the compliant mechanism acting on a needle barrel is simulated with a FEM analysis including the model of non-linearities induced by large deformations and the contact between the needle and the grasping device. Functional prototypes of both NGDs have been constructed and a first experimental assessment of their service capability is finally exposed.

A Multibody/Finite Element Non-Linear Formulation of a Two-Ligament Knee Joint

2008 ◽  
Author(s):  
David Weed ◽  
Luis G. Maqueda ◽  
Michael A. Brown ◽  
Ahmed A. Shabana
Keyword(s):  
Finite Element ◽  
Knee Joint ◽  
Large Deformation ◽  
Large Deformations ◽  
Flexible Structures ◽  
Knee Injuries ◽  
Strain Energy Function ◽  
Rigid Bodies ◽  
Future Research ◽  
Algebraic Equations

The focus of this investigation is to study the mechanics of the human knee using a new method that integrates multi-body system and large deformation finite element algorithms. The major bones in the knee joint consisting of the femur, tibia, fibula are modeled as rigid bodies. The ligaments structures are modeled using the large deformation finite element Absolute Nodal Coordinate Formulation (ANCF) with an implementation of a Neo-Hookean constitutive model that allows for large deformations as experienced in knee flexation and rotation. The Neo-Hookean strain energy function used in this study takes into consideration the near incompressibility of the ligaments. The ANCF is used in the formulation of the algebraic equations that define the ligament/bone rigid connection. A unique feature of the ANCF is that it allows for the deformation of the ligament cross-section. At the ligament/bone connection, the ANCF is used to define a fully constrained joint. This aspect of the model reflects the actual structural mechanics of the knee. In addition, this model will reflect the fact that the geometry, placement and attachment of the two collateral ligaments (the LCL and MCL), are significantly different from what has been used in most knee models developed in previous investigations. The approach described in this paper will provide a more realistic model of the knee and thus more applicable to future research studies. The obtained preliminary results of other applications show that the ANCF can be an effective tool for modeling very flexible structures like ligaments subjected to large deformations. In the future, the ANCF models could assist in examining the mechanics of the knee to study knee injuries and possible prevention means, as well as an improved understanding of the role of each individual ligament in the diagnosis and assessment of disease states, aging and potential therapies.

scholarly journals An SPH framework for fluid–solid and contact interaction problems including thermo-mechanical coupling and reversible phase transitions

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Sebastian L. Fuchs ◽  
Christoph Meier ◽  
Wolfgang A. Wall ◽  
Christian J. Cyron
Keyword(s):  
Phase Transitions ◽  
Contact Interaction ◽  
Computational Effort ◽  
Rigid Bodies ◽  
Body Motion ◽  
Three Dimensions ◽  
Scaling Analysis ◽  
Computational Framework ◽  
Mechanical Coupling ◽  
Reversible Phase

AbstractThe present work proposes an approach for fluid–solid and contact interaction problems including thermo-mechanical coupling and reversible phase transitions. The solid field is assumed to consist of several arbitrarily-shaped, undeformable but mobile rigid bodies, that are evolved in time individually and allowed to get into mechanical contact with each other. The fluid field generally consists of multiple liquid or gas phases. All fields are spatially discretized using the method of smoothed particle hydrodynamics (SPH). This approach is especially suitable in the context of continually changing interface topologies and dynamic phase transitions without the need for additional methodological and computational effort for interface tracking as compared to mesh- or grid-based methods. Proposing a concept for the parallelization of the computational framework, in particular concerning a computationally efficient evaluation of rigid body motion, is an essential part of this work. Finally, the accuracy and robustness of the proposed framework is demonstrated by several numerical examples in two and three dimensions, involving multiple rigid bodies, two-phase flow, and reversible phase transitions, with a focus on two potential application scenarios in the fields of engineering and biomechanics: powder bed fusion additive manufacturing (PBFAM) and disintegration of food boluses in the human stomach. The efficiency of the parallel computational framework is demonstrated by a strong scaling analysis.

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