Multi-Body Damping of a Vane Cluster

2011 ◽  
Author(s):  
Andreas Hartung ◽  
Ulrich Retze
Keyword(s):  
Vibration Amplitude ◽  
Element Model ◽  
Analytical Models ◽  
Blade Vibration ◽  
Body Model ◽  
Good Comparison ◽  
Rigid Body Model ◽  
High Level ◽  
Multi Body ◽  
Level Of Agreement

Spring-damper systems are standard for reducing blade vibration amplitude at vane clusters. Spring-dampers can only be used with an altered geometry of the inner shrouds. In most cases a separation of the inner shrouds is inevitable. In this paper an alternative damping system without changes of the outer inner shroud geometry is developed and analyzed. Two analytical models — a simplified Rigid Body Model and a 3D Finite Element Model show, based on similar results, a good comparison. The analytical results were validated by shaker tests. A high level of agreement between simulation and test was achieved.

Research on the Workpiece Kinematics in Face Lapping with Friction Drive

2012 ◽  
Vol 565 ◽  
pp. 318-323 ◽  
Author(s):  
Uwe Heisel ◽  
Philipp Jakob
Keyword(s):  
Material Removal ◽  
Motion Tracking ◽  
Removal Rate ◽  
Motion Patterns ◽  
Body Model ◽  
Precise Knowledge ◽  
Rigid Body Model ◽  
Reaction Forces ◽  
Multi Body

In face lapping, the achievable material removal rate and surface quality depend strongly on the workpiece kinematics. Hence, the precise knowledge of the kinematics is an important requirement for increasing the efficiency and quality of the superfinishing process. The main focus of experiment is to identify how different workpiece geometries influence the resulting kinematics. The process kinematics in face lapping with friction drive is performed by means of motion tracking. Multi-body simulation allows extending the understanding of the process. Apart from the motion patterns of the lapping process, which were determined before, experimentally established reaction forces are used for verifying the considered rigid body model. A deviation of less than 10 % between the forces determined experimentally and by simulation verifies that it is a promising possibility to assess the kinematics by simulation.

A Finite Element Investigation of a Functional Spine Unit in Conjunction With a Multi-Body Model of the Lumbar Spine for Impact Dynamics

Volume 2 ◽  
2004 ◽  
Author(s):  
Volkan Esat ◽  
Memis Acar
Keyword(s):  
Finite Element ◽  
Lumbar Spine ◽  
Reaction Force ◽  
Element Model ◽  
Fe Model ◽  
Body Model ◽  
Spine Model ◽  
Spinal Segments ◽  
Whole Spine ◽  
Multi Body

In this study, the finite element (FE) technique was used in conjunction with multi-body modelling to simulate and analyse the dynamic behaviour of the spinal segments in order to investigate the effects of impact loadings on the lumbar spine. A 3-D multi-body model of the lumbar spine and an FE model of the L2-L3 motion segment were developed. Both models were validated for flexion and compression loadings, showing good agreements with a previously validated lumbar spine model. The predictions of the multi-body model under dynamic impact loading conditions such as reaction forces at lumbar motion segments were employed as force boundary conditions for the finite element model of the selected functional spine unit (FSU). Stress and pressure in the intervertebral disc element and the reaction force at a specific vertebral level were presented. This approach has the potential to more realistically simulate the dynamics of spinal segments and whole spine, and study the effects on spinal elements.

Numerical Analysis of Vehicle Occupant Responses during Rear Impact Using a Human Body Model

2014 ◽  
Vol 566 ◽  
pp. 480-485 ◽  
Author(s):  
Jonas A. Pramudita ◽  
Shunsuke Kikuchi ◽  
Yuji Tanabe
Keyword(s):  
Finite Element ◽  
Numerical Analysis ◽  
Finite Element Model ◽  
Real World ◽  
Element Model ◽  
Vehicle Occupant ◽  
Body Model ◽  
Rear Impact ◽  
Multi Body ◽  
Impact Simulations

Understanding vehicle occupant responses during real-world rear collision accidents is very important in the development of appropriate safety technologies for neck injury lessening. In this study, numerical analysis of vehicle occupant responses during rear impact were conducted by using a human multi-body model, a seat finite element model and crash accelerations obtained from real-world accidents. The human multi-body model was developed based on the body characteristics of a typical Japanese male, including the outer body geometry, inertial properties of body segments and passive joint characteristics. The seat finite element model was extracted from a detailed car finite element model. A small modification was done to the seat model to deal with the rear impact simulations. The crash accelerations were obtained from the drive recorder database of rear collision accidents occurred in Japan. Several crash accelerations were selected and used as input conditions during the rear impact simulations. Kinematic responses of the occupants during the accidents can be reasonably predicted by the simulations. Furthermore, different level of accelerations leads to different kinematics responses that may cause variation in injury occurrence and injury severity.

Coupled-Field Analysis of the Compliant Slider Mechanism with Rectangle Flexure Hinges Based on ANSYS

2011 ◽  
Vol 189-193 ◽  
pp. 1897-1900
Author(s):  
Lei Duan ◽  
Li Fang Qiu ◽  
Hai Shan Weng ◽  
Zhi Yong Xie
Keyword(s):  
Finite Element ◽  
Rigid Body ◽  
Element Model ◽  
Field Analysis ◽  
Flexure Hinges ◽  
Body Model ◽  
Coupled Field ◽  
Rigid Body Model ◽  
Relationship Of ◽  
The Relationship

The compliant slider mechanism with rectangle flexure hinges was designed, and its pseudo-rigid-body model was built. The theoretical value of the relationship between force and displacement was given after analysis; the electrostatic-structural-coupled field finite element model of this mechanism was also built and analyzed by ANSYS, and the simulation value of the relationship between voltage and displacement was obtained; According to the relationship of voltage and force, the theoretical value was compared with the simulation value. The result indicates that the model is valid and the analysis is correct.

scholarly journals Influence of External Factors on Airborne Missile’s Horizontal Backward Launching

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Xiao Pan ◽  
Yi Jiang ◽  
Dong Hu ◽  
Huihui Guan
Keyword(s):  
Finite Element ◽  
Rigid Body ◽  
Pitch Angle ◽  
Random Vibration ◽  
Element Model ◽  
Body Model ◽  
Ejection Force ◽  
Ejection Process ◽  
Rigid Body Model ◽  
The Finite Element Model

This paper studies the influence of different external disturbance factors on the horizontal backward separation of airborne missiles on large transport aircraft. The method of comparison with experiment was adopted to verify the accuracy of the finite element model during the ejection process. By comparing the finite element model, it was confirmed that the all rigid body model and partly rigid body model are inaccurate in calculating the pitch angle and pitch velocity of the missile separation. Finally, the influences of ejection force, random vibration, and missile loading position on the ejection process are analyzed. The analysis found that the ejection force and the sliding distance will increase the vibration of the launching platform, therefore increase the separation pitch angle and the pitch velocity of the missile, but the influence of random vibration on platform is much greater than the other two factors, and it will also introduce randomness into the movement of the missile.

Generating Parameters of a Multi-Body Meniscus Model From Experimental Data

2010 ◽  
Author(s):  
Gavin Paiva ◽  
Trent Guess ◽  
Mohammad Kia
Keyword(s):  
Experimental Data ◽  
Material Properties ◽  
Element Model ◽  
Contact Forces ◽  
Large Strains ◽  
Body Model ◽  
Physiological Loading ◽  
Tension And Compression ◽  
Multi Body ◽  
Force Displacement

The meniscus is a crucial anatomical structure in the mechanics of vertebrate hind legs [3]. Menisci function primarily by distributing the tibio-femoral contact forces, and thereby reducing the stress in the articular cartilage of the knee joint. As the meniscus is a flexible body that undergoes large strains, it is typically ignored in rigid-body biomechanical simulations. One documented method of including this factor in the multi-body framework is to represent the menisci as discrete bodies connected by linear 6-axis spring and damper elements [2]. The difficulty arises in determining the stiffnesses and viscosities that correspond to the material properties of the real meniscus. Material properties have previously been determined by a design of experiments approach to match the force displacement behavior of a multi-body model to a linear finite element model. This study explores a method of determining the said properties from experimental data collected in a semi-physiological loading, where the force orientation is principally circumferential tension and compression in the other directions.

Design of a Single-Acting Constant-Force Actuator Based on Dielectric Elastomers

2008 ◽  
Author(s):  
Giovanni Berselli ◽  
Rocco Vertechy ◽  
Gabriele Vassura ◽  
Vincenzo Parenti Castelli
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Compliant Mechanism ◽  
Structural Parameters ◽  
Dielectric Elastomer ◽  
Constant Force ◽  
Element Analysis ◽  
Body Model ◽  
Rigid Body Model ◽  
Supporting Frame

The interest in actuators based on dielectric elastomer films as a promising technology in robotic and mechatronic applications is increasing. The overall actuator performances are influenced by the design of both the active film and the film supporting frame. This paper presents a single-acting actuator which is capable of supplying a constant force over a given range of motion. The actuator is obtained by coupling a rectangular film of silicone dielectric elastomer with a monolithic frame designed to suitably modify the force generated by the dielectric elastomer film. The frame is a fully compliant mechanism whose main structural parameters are calculated using a pseudo-rigid-body model and then verified by finite element analysis. Simulations show promising performance of the proposed actuator.

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