Virtual characterization of nonlocal continuum damage model parameters using a high fidelity finite element model

2021 ◽  
Vol 256 ◽  
pp. 113073
Author(s):  
Johannes Reiner ◽  
Xiaodong Xu ◽  
Navid Zobeiry ◽  
Reza Vaziri ◽  
Stephen R. Hallett ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Damage Model ◽  
Element Model ◽  
Model Parameters ◽  
High Fidelity ◽  
Continuum Damage ◽  
Nonlocal Continuum ◽  
Continuum Damage Model

scholarly journals Force-State Characterization of Struts Using Pinned Joints

1997 ◽  
Vol 4 (2) ◽  
pp. 103-113 ◽  
Author(s):  
Brook D. Ferney ◽  
Steven L. Folkman
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Research Effort ◽  
Element Model ◽  
Mapping Technique ◽  
Model Parameters ◽  
The Finite Element Model ◽  
Pinned Joints

As part of a research effort to study the microgravity dynamics of a truss with pinned joints, a single strut with a single clevis-tang pinned joint was characterized. Experimental data was collected using a force-state mapping technique. The strut was subjected to axial dynamic loads and the response of the strut was measured. The force-state map aids visualization of the strut dynamics. Finite element modeling of the response was explored. An example is presented that uses a method of manual determination of the finite element model parameters. The finite element model results correspond well with the measured strut response.

Characterization of Nonlinear Coupled Dynamics in Sandwich Structures

2008 ◽  
Author(s):  
Ioannis T. Georgiou
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Geometric Nonlinearity ◽  
Sandwich Structures ◽  
Normal Modes ◽  
Element Model ◽  
Nonlinear Normal Modes ◽  
High Fidelity ◽  
Coupled Dynamics ◽  
Nonlinear Normal

In this work, the nonlinear coupled dynamics of a sandwich structure with hexagonal honeycomb core are characterized in terms of Proper Orthogonal Decomposition modes. A high fidelity nonlinear finite element model is derived to describe geometric nonlinearity and displacement and rotation fields that govern the coupled dynamics. Contrary to equivalent continuum models used to predict vibration properties of lattice and sandwich structures, a high fidelity finite element model allows for a quite detailed description of the distributed complicated geometric nonlinearity of the core. It was found that the free dynamics excited by a blast load and the forced dynamics excited by a harmonic force posses POD modes which are localized in space and time. The processing of the simulated dynamics by the Time Discrete Proper Transform forms a means to study the nonlinear coupled dynamics of sandwich structures in the context of nonlinear normal modes of vibration and reduced order models.

scholarly journals Failure Analysis of Composite Pinned Joints Based on Continuum Damage Mechanics

2018 ◽  
Vol 36 (5) ◽  
pp. 848-855
Author(s):  
Hongliang Tuo ◽  
Xiaoping Ma ◽  
Zhixian Lu
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Damage Mechanics ◽  
Continuum Damage Mechanics ◽  
Element Model ◽  
Fracture Plane ◽  
Continuum Damage ◽  
Bearing Strength ◽  
Matrix Damage ◽  
Pinned Joints

The paper conducted bearing tests on composite pinned joints with four different stacking sequences. The bearing strength and bearing chord stiffness were obtained. The influence of stacking sequences on failure modes, bearing strength and bearing chord stiffness was discussed. Based on continuum damage mechanics, a three-dimensional finite element model of composite pinned joint under bearing load was built, where the maximum strain criterion was employed for initiation and bi-liner damage constitutive relation for revolution of fiber damage, while the physical-based Puck criterion was used for matrix damage initiation, and matrix damage revolution depended on the effective strain on the fracture plane. The failure mode, bearing strength and bearing chord stiffness of composite pinned joint were discussed with this model under which the non-linear shear behavior and in-situ strength effects were considered. Good agreements between test results and numerical simulations validates the accuracy and applicability of the finite element model.

An Effective Method for Determining Finite Element Model Parameters of Rotor Elastic Support System

2011 ◽  
Vol 141 ◽  
pp. 191-197
Author(s):  
Yong Xing Wang ◽  
Jiang Yan ◽  
Sheng Ze Wang
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Support System ◽  
Structural Parameters ◽  
Element Model ◽  
Elastic Support ◽  
Asymmetric Structure ◽  
Model Parameters ◽  
Equivalent Stiffness ◽  
Rolling Ball

A finite element model of the elastic support rotor system based on the corresponding experimental model was established. According to the principle of two types of model with an equal first order critical speed, the equivalent stiffness and damping of a rolling ball bearing support system with rubber rings determined by experiment were transferred into the finite element model. Then, the dynamic behavior of rotor systems with symmetric and asymmetric structure, different support system stiffness and support span were calculated and analyzed respectively. At last, the influence of the rotor structural parameters on the equivalent stiffness of elastic bearing support system obtained by experiment was pointed out.

Numerical and Experimental Analysis of Self Piercing Riveting Process with Carbon Fiber-Reinforced Plastic and Aluminium Sheets

2013 ◽  
Vol 554-557 ◽  
pp. 1045-1054 ◽  
Author(s):  
Welf Guntram Drossel ◽  
Reinhard Mauermann ◽  
Raik Grützner ◽  
Danilo Mattheß
Keyword(s):  
Finite Element ◽  
Carbon Fiber ◽  
Finite Element Model ◽  
Simulation Model ◽  
Process Parameters ◽  
Process Model ◽  
Element Model ◽  
Model Parameters ◽  
Fiber Reinforced ◽  
Carbon Fiber Reinforced

In this study a numerical simulation model was designed for representing the joining process of carbon fiber-reinforced plastics (CFRP) and aluminum alloy with semi-tubular self-piercing rivet. The first step towards this goal is to analyze the piercing process of CFRP numerical and experimental. Thereby the essential process parameters, tool geometries and material characteristics are determined and in finite element model represented. Subsequently the finite element model will be verified and calibrated by experimental studies. The next step is the integration of the calibrated model parameters from the piercing process in the extensive simulation model of self-piercing rivet process. The comparison between the measured and computed values, e.g. process parameters and the geometrical connection characteristics, shows the reached quality of the process model. The presented method provides an experimental reliable characterization of the damage of the composite material and an evaluation of the connection performances, regarding the anisotropic property of CFRP.

Application of a FRF Based Model Updating Technique for the Validation of Finite Element Models of Components of the Automotive Industry

1995 ◽  
Author(s):  
Stefan Lammens ◽  
Marc Brughmans ◽  
Jan Leuridan ◽  
Ward Heylen ◽  
Paul Sas
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Automotive Industry ◽  
Stiffness Matrix ◽  
Model Updating ◽  
Dynamic Stiffness ◽  
Element Model ◽  
Model Parameters ◽  
Finite Element Models ◽  
Analytical Dynamic

Abstract This paper presents two applications of the RADSER model updating technique (Lammens et al. (1995) and Larsson (1992)). The RADSER technique updates finite element model parameters by solution of a linearised set of equations that optimise the Reduced Analytical Dynamic Stiffness matrix based on Experimental Receptances. The first application deals with the identification of the dynamic characteristics of rubber mounts. The second application validates a coarse finite element model of a subframe of a Volvo 480.

Design and characterization of a hybrid soft gripper with active palm pose control

2020 ◽  
Vol 39 (14) ◽  
pp. 1668-1685 ◽  
Author(s):  
Vignesh Subramaniam ◽  
Snehal Jain ◽  
Jai Agarwal ◽  
Pablo Valdivia y Alvarado
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Composite Structure ◽  
Element Model ◽  
Open Loop ◽  
Aspect Ratios ◽  
Maximum Payload ◽  
Wide Range ◽  
Pose Control

The design and characterization of a soft gripper with an active palm to control grasp postures is presented herein. The gripper structure is a hybrid of soft and stiff components to facilitate integration with traditional arm manipulators. Three fingers and a palm constitute the gripper, all of which are vacuum actuated. Internal wedges are used to tailor the deformation of a soft outer reinforced skin as vacuum collapses the composite structure. A computational finite-element model is proposed to predict finger kinematics. Thanks to its active palm, the gripper is capable of grasping a wide range of part geometries and compliances while achieving a maximum payload of 30 N. The gripper natural softness enables robust open-loop grasping even when components are not properly aligned. Furthermore, the grasp pose of objects with various aspect ratios and compliances can be robustly maintained during manipulation at linear accelerations of up to 15 m/s2 and angular accelerations of up to 5.23 rad/s2.

Finite element model for the characterization of deleterious phases by eddy current technique

2012 ◽  
Vol 39 (1-4) ◽  
pp. 305-310 ◽  
Author(s):  
Maria C.L. Areiza ◽  
Rodrigo Sacramento ◽  
Joao M.A Rebello ◽  
Rubem L. Sommer ◽  
Diego Gonzalez
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Eddy Current ◽  
Element Model ◽  
Current Technique

Contact Stress and Linearized Modal Predictions of As-Built Preloaded Assembly

2020 ◽  
Vol 142 (5) ◽  
Author(s):  
Adam R. Brink ◽  
Robert J. Kuether ◽  
Matthew D. Fronk ◽  
Bryan L. Witt ◽  
Brendan L. Nation
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Contact Area ◽  
Element Model ◽  
High Fidelity ◽  
Vibration Modes ◽  
Low Level ◽  
Pressure Sensitive ◽  
Sensitive Film ◽  
Pressure Sensitive Film

Abstract The member stiffness and pressure distribution in a bolted joint is significantly influenced by the contact area of the mechanical interface under a prescribed preload force. This research explores the influence of as-built surface profiles for nominally flat interfaces of a C-Beam assembly with two well-defined contact regions. A high-fidelity finite element model is created such that the model uncertainty is minimized by updating and calibrating the piece parts prior to the preload assembly procedure. The model is then assembled and preloaded to evaluate the contact stresses and contact area for both nominally flat and perturbed non-flat surfaces based on three-dimensional surface topography measurements. The predicted pressures are validated with digitized pressure-sensitive film measurements. The high-fidelity modeling reveals how the compliance and thickness of the pressure-sensitive film alter the measured pressures, leading to incorrect evaluations of the stresses and contact area in the joint. The resulting low-level dynamic behavior of the preloaded assembly is shown to be sensitive to the true contact area by linearizing the nonlinear finite element model about the preloaded equilibrium and performing a computational modal analysis. The resonant frequencies are validated with experimental measurements to demonstrate the effect of the contact area on the modal characteristics of the bolted assembly. Vibration modes and loading patterns exhibit varying levels of sensitivity to the contact area in the joint, leading to an improved physical understanding of the influence of contact mechanics on the low-level linear vibration modes of jointed assemblies.

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