Real-Time Finite Element Modelling With Haptic Support

Author(s):  
Jeffrey Berkley ◽  
Mark Ganter ◽  
Suzanne Weghorst ◽  
Hayes Gladstone ◽  
Gregory Raugi ◽  
...  

Abstract This paper presents the preliminary results of a new real-time finite element system which supports haptic (i.e. force) feedback to the user. The methodology of the system is based on linear finite-element analysis. Further, this system was originally developed as part of a real-time skin surgery simulator with the Human Interface Technology Lab and, the Division of Dermatology at the University of Washington Medical School. We are currently exploring its use and development as a new engineering design tool.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Graeme R. Paul ◽  
Esther Wehrle ◽  
Duncan C. Tourolle ◽  
Gisela A. Kuhn ◽  
Ralph Müller

AbstractMechanical loading allows both investigation into the mechano-regulation of fracture healing as well as interventions to improve fracture-healing outcomes such as delayed healing or non-unions. However, loading is seldom individualised or even targeted to an effective mechanical stimulus level within the bone tissue. In this study, we use micro-finite element analysis to demonstrate the result of using a constant loading assumption for all mouse femurs in a given group. We then contrast this with the application of an adaptive loading approach, denoted real time Finite Element adaptation, in which micro-computed tomography images provide the basis for micro-FE based simulations and the resulting strains are manipulated and targeted to a reference distribution. Using this approach, we demonstrate that individualised femoral loading leads to a better-specified strain distribution and lower variance in tissue mechanical stimulus across all mice, both longitudinally and cross-sectionally, while making sure that no overloading is occurring leading to refracture of the femur bones.


Author(s):  
Yongjian Sun ◽  
Bo Xu

In this paper, in order to solve the calculation problem of creep damage of steam turbine rotor, a real-time calculation method based on finite element model is proposed. The temperature field and stress field of the turbine rotor are calculated using finite element analysis software. The temperature data and stress data of the crucial positions are extracted. The data of temperature, pressure, rotational speed, and stress relating to creep damage calculation are normalized. A real-time creep stress calculation model is established by multiple regression method. After that, the relation between stress and damage function is analyzed and fitted, and creep damage is calculated in real-time. A creep damage real-time calculation system is constructed for practical turbine engineering. Finally, a numerical simulation experiment is designed and carried out to verify the effectiveness of this novel approach. Contributions of present work are that a practical solution for real-time creep damage prediction of steam turbine is supplied. It relates the real-time creep damage prediction to process parameters of steam turbine, and it bridges the gap between the theoretical research works and practical engineering.


2005 ◽  
Vol 2 (1) ◽  
pp. 53-60 ◽  
Author(s):  
C. W. Kennedy ◽  
J. P. Desai

The primary goal of this paper is to provide force feedback to the user using vision-based techniques. The approach presented in this paper can be used to provide force feedback to the surgeon for robot-assisted procedures. As proof of concept, we have developed a linear elastic finite element model (FEM) of a rubber membrane whereby the nodal displacements of the membrane points are measured using vision. These nodal displacements are the input into our finite element model. In the first experiment, we track the deformation of the membrane in real-time through stereovision and compare it with the actual deformation computed through forward kinematics of the robot arm. On the basis of accurate deformation estimation through vision, we test the physical model of a membrane developed through finite element techniques. The FEM model accurately reflects the interaction forces on the user console when the interaction forces of the robot arm with the membrane are compared with those experienced by the surgeon on the console through the force feedback device. In the second experiment, the PHANToM haptic interface device is used to control the Mitsubishi PA-10 robot arm and interact with the membrane in real-time. Image data obtained through vision of the deformation of the membrane is used as the displacement input for the FEM model to compute the local interaction forces which are then displayed on the user console for providing force feedback and hence closing the loop.


Author(s):  
Kaijun Zhu ◽  
Yu Qian ◽  
J. Riley Edwards ◽  
Bassem O. Andrawes

A rail joint typically is one of the weakest elements of a track superstructure, primarily because of discontinuities in its geometric and mechanical properties and the high-impact loads induced by these discontinuities. The development of continuously welded rail has significantly reduced the number of rail joints, but many bolted joints remain installed in rail transit systems. Because of the unique loading environment of a rail transit system (especially high-frequency, high-repetition loads), defects related to bolted rail joints (e.g., joint bar failures, bolt hole cracks, and cracks in the upper fillet) continue to cause service failures and can pose derailment risks. Recent research in the Rail Transportation and Engineering Center at the University of Illinois at Urbana–Champaign has focused on investigating crack initiation in the bolt hole and fillet areas of bolted rail joints. Stress distribution was investigated at the rail-end bolt hole and upper fillet areas of standard, longer, and thicker joint bars under static loading conditions. Numerical simulations were organized into a comprehensive parametric analysis performed with finite element modeling. Preliminary results indicated that the longer joint bar performed similarly to the standard joint bar but the thicker joint bar reduced rail vertical displacement and rail upper fillet stresses compared with the standard joint bar. However, the thicker joint bar also may generate higher stresses at the rail-end bolt hole. Additionally, joint bar performance was dependent on the rail profile and bolt hole location.


Author(s):  
Paul M. Kurowski

The Finite Element Analysis (FEA) is becoming increasingly popular among design engineers using it as one of many product design tools. Safe and cost efficient use of FEA as a product design tool requires training, different from that presently found in undergraduate curriculum of mechanical engineering students. The specific requirements of design engineers for training in the field of FEA have been addressed by the author in a number of professional development courses in FEA, catering specifically to the needs of design engineers. This paper discuses tools and methods used in the development and delivery of these courses and their applicability to the undergraduate courses taught in Canadian Engineering schools.


2005 ◽  
Vol 127 (1) ◽  
pp. 34-37 ◽  
Author(s):  
Ravi Chandra Sikakollu ◽  
Lemmy Meekisho ◽  
Andres LaRosa

This paper deals with the design and analysis of a horizontal thermal actuator common in MEMS applications using Finite Element Analysis; with the objective of exploring means to improve its sensitivity. The influence of variables like voltage and the dimensions of the cold arm of the actuator unit were examined by comprehensive, coupled thermal-stress analyses. Simulation results from this study showed that the sensitivity of the actuator increases with the applied voltage as well as the width of the cold arm of the thermal actuator. An important observation made from this study is that the size and thermal boundary conditions at the fixed end of the actuator primarily control the stroke and the operating temperature of the actuator for a given potential difference between cold and hot arms. The coupled field analyses also provided a design tool for maximizing the service voltage and dimensional variables without compromising the thermal or structural integrity of the actuator.


2012 ◽  
Vol 226-228 ◽  
pp. 2128-2131
Author(s):  
Tao Huang ◽  
Jun Pu Wang ◽  
Fu Wan ◽  
Shao Wei Chen ◽  
Yao Dong

Aiming at the design feature and the operating of K-type derrick, an effective method used to stress real-time monitoring consider environmental loading is proposed. The challenge to the South China Sea offshore drilling derrick is a illustration. The derrick corrosion and wall thinning conditions is be considered, then using finite element software analyze derrick structure of static analysis, get the higher force about main member of derrick. Based on finite element analysis, select the key parts layout of measuring points, then monitor derrick stress under nine storms environmental loading and extreme work condition. The measured data results show that: the nine storms environmental load affect capacity of drilling significantly, the different parts of the main member stress have the different degrees of influence by environmental load, the maximum can reach 50.8%. This real-time monitoring method of stress, can protect the safety of marine operations, has a certain value of engineering application.


2017 ◽  
Vol 21 (2) ◽  
pp. 422-438 ◽  
Author(s):  
G Martakos ◽  
JH Andreasen ◽  
C Berggreen ◽  
OT Thomsen

A novel crack arresting device is implemented in foam-cored composite sandwich beams and tested using the Sandwich Tear Test (STT) configuration. A finite element model of the setup is developed, and the predictions are correlated with observations and results from a recently conducted experimental fatigue test study. Based on a linear elastic fracture mechanics approach, the developed FE model is utilised to simulate crack propagation and arrest in foam-cored sandwich beam specimens subjected to fatigue loading conditions. The effect of the crack arresters on the fatigue life is analysed, and the predictive results are subsequently compared with the observations from the previously conducted fatigue tests. The FE model predicts the energy release rate and the mode mixity based on the derived crack surface displacements, utilising algorithms for the prediction of accelerated fatigue crack growth as well as the strain field evolution in the vicinity of the crack tip on the surface of the sandwich specimens. It is further shown that the developed finite element analysis methodology can be used to gain a deeper insight onto the physics and behavioural characteristics of the novel peel stopper concept, as well as a design tool that can be used for the implementation of crack arresting devises in engineering applications of sandwich components and structures.


Author(s):  
Graeme R. Paul ◽  
Esther Wehrle ◽  
Duncan C. Tourolle ◽  
Gisela A. Kuhn ◽  
Ralph Müller

AbstractMechanical loading allows both investigation into the mechano-regulation of fracture healing as well as interventions to improve fracture-healing outcomes such as delayed healing or non-unions. However, loading is seldom individualised or even targeted to an effective mechanical stimulus level within the bone tissue. In this study, we use micro-finite element analysis to demonstrate the result of using a constant loading assumption for all mouse femurs in a given group. We then contrast this with the application of an adaptive loading approach, denoted real time Finite Element (rtFE) adaptation, in which micro-computed tomography images provide the basis for micro-FE based simulations and the resulting strains are manipulated and targeted to a reference distribution. Using this approach, we demonstrate that individualised femoral loading leads to a better-specified strain distribution and lower variance in tissue mechanical stimulus across all mice, both longitudinally and cross-sectionally, while making sure that no overloading is occurring leading to refracture of the femur bones.


Author(s):  
Victor Caraveo ◽  
Scott Lovald ◽  
Tariq Khraishi ◽  
Jon Wagner ◽  
Brett Baack

FE modeling of biological tissues and physiological behavior is now becoming common practice with the improvement in finite element analysis (FEA) software and the significant increase in capability of computing resources. There are many uses for FEA of this nature, one of which has been simulating the mechanical behavior of implant devices for fracture repair. FE analysis offers insight into the mechanistic behavior of fixation plates used in rigid internal fixation and, if modeled carefully, could eventually become an accurate design tool.


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