Compression Experiment And Failure Analysis of Additive Manufactured Multi-Layer Lattice Sandwich Structure

2021 ◽  
Author(s):  
Jun Yan ◽  
Cuncun Jiang ◽  
Zhirui Fan ◽  
Qi Xu ◽  
Hongze Du ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Failure Mode ◽  
Sandwich Structure ◽  
Sandwich Structures ◽  
Element Model ◽  
Structural Deformation ◽  
Displacement Curve ◽  
Static Compression ◽  
Quasi Static Compression

The rapid development of additive manufacturing technology provides a new opportunity for the fabrication and research of multi-layer lattice sandwich structures, and thereby some excellent performances can be further discovered. Based on the manufacturing-experiment-analysis technical route, the failure mode of the additive manufactured aluminum multi-layer alloy lattice sandwich structure under quasi-static compression is systematically studied in this paper. Through the combination of experimental observation and finite element analysis, the complex failure mechanism of the multi-layer lattice sandwich structure is revealed. The results show that the multi-layer lattice sandwich structure under quasi-static compression conditions mainly manifests as a layer-by-layer failure mode of the internal lattice structure, which includes the yield, plastic buckling and material damage. At the same time, in comparison with the force–displacement curve and the structural deformation in the key locations, the analysis accuracy of the finite element model can be verified by the compression experiment. Based on the verified finite element model, the most significant influence of different face panel thicknesses, as well the rod radiuses and tilting angles on the energy absorption (EA) is identified via sensitivity analysis. Furthermore, size factors on the structural EA are revealed. This study can provide a helpful guidance for the design of multi-layer lattice sandwich structures in practical applications.

STUDY ON FAILURE MODE OF HUSK MORTAR ENERGY-SAVING WALLBOARDS

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
Yu Zhang ◽  
Qingwen Zhang ◽  
Jian Zhao ◽  
Guangchun Zhou
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Energy Saving ◽  
Failure Mode ◽  
Vertical Direction ◽  
Element Model ◽  
Displacement Curve ◽  
Element Analysis ◽  
New Type ◽  
The Finite Element Model

This paper focuses on husk mortar wallboard, which is a new type of energy-saving composite wallboard with new materials and complex working mechanism. There are eight total different dimensioned panels tested. Six of them are openings (window or door), with different opening rates; the other two are full panels with same dimensions. Based on the experimental data, they are analyzed under both horizontal and vertical direction loading, combined with the finite element analysis to reveal the working characteristics. The finite element model of husk mortar energy-saving wallboards is established by ANSYS software. Finally, the finite element results are compared with the experimental results from three aspects: ultimate load, failure mode and load displacement curve, which verifies the correctness of the finite element model.

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.

Damage quantification in foam core sandwich composites via finite element model updating and artificial neural networks

2020 ◽  
Vol 234 (21) ◽  
pp. 4288-4304
Author(s):  
Ali Mardanshahi ◽  
Masoud Mardanshahi ◽  
Ahmad Izadi
Keyword(s):  
Neural Networks ◽  
Finite Element ◽  
Artificial Neural Networks ◽  
Finite Element Model ◽  
Model Updating ◽  
Sandwich Structures ◽  
Element Model ◽  
Foam Core ◽  
Damage Quantification ◽  
Artificial Neural

The main idea of this paper is to propose a nondestructive evaluation (NDE) system for two types of damages, core cracking and skin/core debonding, in fiberglass/foam core sandwich structures based on the inverse eigensensitivity-based finite element model updating using the modal test results, and the artificial neural networks. First, the modal testing was conducted on the fabricated fiberglass/foam core sandwich specimens, in the intact and damaged states, and the natural frequencies were extracted. Finite element modeling and inverse eigensensitivity-based model updating of the intact and damaged sandwich structures were conducted and the parameters of the models were identified. Afterward, the updated finite element models were employed to generate a large dataset of the first five harmonic frequencies of the damaged sandwich structures with different damage sizes and locations. This dataset was adopted to train the machine learning models for detection, localization, and size estimation of the core cracking and skin/core debonding damages. A multilayer perceptron neural network classification model was used for detection of types of damages and also a multilayer perceptron neural network regression model was fitted to the dataset for automatically estimation of the locations and dimensions of damages. This intelligent system of damage quantification was also used to make predictions on real damaged specimens not seen by the system. The results indicated that the extracted natural frequencies from the accurate finite element model, in coordination with the experimental data, and using the artificial neural networks can provide an effective system for nondestructive evaluation of foam core sandwich structures.

Deformation Index–Based Modeling of Transient, Thermo-mechanical Rolling Resistance for a Nonpneumatic Tire

2013 ◽  
Vol 41 (2) ◽  
pp. 82-108 ◽  
Author(s):  
James M. Gibert ◽  
Balajee Ananthasayanam ◽  
Paul F. Joseph ◽  
Timothy B. Rhyne ◽  
Steven M. Cron
Keyword(s):  
Finite Element ◽  
Steady State ◽  
Finite Element Model ◽  
Rolling Resistance ◽  
Element Model ◽  
Lumped Parameter Model ◽  
Structural Deformation ◽  
Elastic Response ◽  
Full Potential ◽  
Deformation Index

ABSTRACT When competing in performance with their pneumatic counterparts, nonpneumatic tires should have several critical features, such as low energy loss when rolling over obstacles, low mass, low stiffness, and low contact pressure. In recent years, a nonpneumatic tire design was proposed to address each of these critical issues [1]. In this study, the steady state and transient energy losses due to rolling resistance for the proposed nonpneumatic tire are considered. Typically, such an analysis is complex because of the coupling of temperature on the structural deformation and the viscoelastic energy dissipation, which requires an iterative procedure. However, researchers have proposed a simplified analysis by using the sensitivity of the tire's elastic response to changes in material stiffness through a deformation index [2–4]. In the current study, the method is exploited to its full potential for the nonpneumatic tire due to the relatively simple nature of deformation in the tire's flexible ring and the lack of several complicating features present in pneumatic tires, namely, a heated air cavity and the complex stress state due to its composite structure. In this article, two models were developed to predict the transient and steady-state temperature rise. The first is a finite element model based on the deformation index approach, which can account for thermo-mechanical details in the tire. Motivated by the simplicity of the thermo-behavior predicted by this finite element model, a simple lumped parameter model for temperature prediction at the center of the shear band was developed, which in many cases compares very well with the more detailed finite element approach due to the nature of the nonpneumatic tire. The finite element model can be used to, for example, explore the design space of the nonpneumatic tire to reach target temperatures by modifying heat transfer coefficients and/or material properties.

Finite Element Model to Simulate the Spacer Grid Buckling Characteristics

2020 ◽  
Author(s):  
Youngik Yoo ◽  
Joongjin Kim ◽  
Kyongbo Eom ◽  
Hyeongkoo Kim
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Fuel Assembly ◽  
Nuclear Fuel ◽  
Grid Cell ◽  
Element Model ◽  
Spacer Grid ◽  
Static Compression ◽  
Fuel Rod ◽  
Nuclear Fuel Assembly

Abstract The purpose of this study is to develop a finite element model that accurately describes the buckling behavior of a spacer grid. The spacer grid is the most important component of a nuclear fuel assembly and supports the fuel rod with a structurally sufficient buckling strength. Therefore, the development of a reliable spacer grid model is essential to evaluate the mechanical integrity of a nuclear fuel assembly. To achieve this objective, a three-dimensional finite element model was proposed to simulate the buckling characteristics and mechanical behavior of a PWR spacer grid. To simulate the exact mechanical properties of the spacer grid cell, the parameter values required for the model were determined by conducting a fuel rod drag test and spacer grid spring/dimple stiffness test. Finally, a spacer grid static compression test and dynamic impact test were performed according to the gap size of the spacer grid cell, and the model was verified by comparing the test and analysis results. The results obtained using the developed spacer grid finite element model agreed well with the mechanical test results, and it was confirmed that both the buckling characteristics and mechanical behaviors of the model were accurately simulated by the proposed model.

Damping Control in a Sandwich Structure With SMP Core

2015 ◽  
Author(s):  
Pauline Butaud ◽  
Morvan Ouisse ◽  
Emmanuel Foltête
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Sandwich Structure ◽  
Damping Ratio ◽  
Shape Memory Polymer ◽  
Viscoelastic Model ◽  
Element Model ◽  
Numerical Approach ◽  
Wide Frequency Range ◽  
Frequency Range

A shape memory polymer (SMP), the tBA/PEGDMA, is elaborated and characterized. The dynamic mechanical characterization of this SMP highlights promising damping properties. The frequency and temperature dependency of the SMP is represented by a viscoelastic model allowing the introduction of the material in the design process of complex structures. A composite sandwich is developed by coupling the SMP with aluminum skins. A finite element model is developed for modeling the behavior of the SMP when integrated in a sandwich structure. The damping performances obtained by the numerical approach are validated experimentally using modal analysis. The experimental results are found to be in good agreement with the predictions of the finite element model. Furthermore, it is found that the controlled heating of the SMP core allows damping the structure over a wide frequency range. The SMP core temperature is tuned from the time-temperature superposition through a calibration curve to correspond to optimal values of damping ratio in the frequency range of interest; a vibration attenuation of about 20dB is observed.

Finite element model for damping optimization of viscoelastic sandwich structures

2013 ◽  
Vol 66 ◽  
pp. 34-39 ◽  
Author(s):  
J.S. Moita ◽  
A.L. Araújo ◽  
C.M. Mota Soares ◽  
C.A. Mota Soares
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Sandwich Structures ◽  
Element Model
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