Monitoring of resin flow front and degree of cure in vacuum‐assisted resin infusion process using multifunctional piezoelectric sensor network

2020 ◽  
Author(s):  
Xiao Liu ◽  
Yukun Li ◽  
Jianjian Zhu ◽  
Yishou Wang ◽  
Xinlin Qing

2017 ◽  
Vol 36 (10) ◽  
pp. 780-794 ◽  
Author(s):  
Liangkai Ma ◽  
Siddharth R Athreya ◽  
Rujul Mehta ◽  
Dev Barpanda ◽  
Asjad Shafi

This paper presents an experimentally validated model to simulate the nonisothermal resin infusion and cure processes in a relatively large and thick composite laminate fabricated using vacuum-assisted resin transfer molding. Compaction effects were accounted for by using a step-wise scheme wherein the panel was divided into three discrete zones along the flow direction, with each zone being assigned different porosities and other material properties. The experimentally observed dynamic evolution of the resin flow front profile due to permeability difference between the high-permeable infusion medium and the glass-fiber preform as well as the heat transfer in the preheated system was captured accurately. Both model predictions and experimental measurements indicate subtle variation in the spatiotemporal distributions of temperature and degrees of resin cure from the infusion stage can result in large differences in the resin cure profile across the laminate, which may cause undesirable residual stresses in large composites.



2021 ◽  
pp. 147592172110332
Author(s):  
Mehrdad Ghyabi ◽  
Hamidreza Nemati ◽  
Ehsan Dehghan-Niri

In this article, the coverage area prediction of piezoelectric sensor network for detecting a specific type of under-surface crack in plate-like structures is addressed. In particular, this article proposes a simplified framework to estimate the coverage of any given sensor network arrangement when a critical defect is known. Based on numerical results from finite element methods (FEM), a simplified framework to estimate coverage area of any given network arrangement is developed. Using such a simplified framework, one can avoid time-consuming procedure of evaluating numerous FEM models in estimating sensor network coverage. Back-scatter fields of partial cracks are estimated using a proposed function, whose parameters are estimated from the results of a limited number of FEM simulations. The proposed function efficiently predicts the back-scattered field of any combination of transmitters and receivers for a given crack geometry. Superposition is used to estimate the coverage area of an arbitrary piezoelectric (e.g., PZT) sensor network. It is shown that the coverage area of a sensor network depends on both sensor network geometry and defect properties (e.g., crack inclination) and it is not necessarily a linear function of the number of sensors. Furthermore, it is shown that the network arrangement has an important effect on the geometry of the coverage area. Experimental results of a network of 14 PZTs in two clusters confirm the accuracy of the method.



Author(s):  
Ethan R Pedneau ◽  
Su Su Wang

Abstract Determination of permeability of thick-section glass fabric preforms with fabric layers of different architectures is critical for manufacturing large, thick composite structures with complex geometry, such as wind turbine blades. The thick-section reinforcement permeability is inherently three-dimensional and needs to be obtained for accurate composite processing modeling and analysis. Numerical simulation of the liquid stage of vacuum-assisted resin infusion molding (VARIM) is important to advance the composite manufacturing process and reduce processing-induced defects. In this research, the 3D permeability of thick-section E-glass fabric reinforcement preforms is determined and the results are validated by a comparison between flow front progressions from experiments and from numerical simulations using ANSYS Fluent software. The orientation of the principal permeability axes were unknown prior to experiments. The approach used in this research differs from those in literature in that the through-thickness permeability is determined as a function of flow front positions along the principal axes and the in-plane permeabilities and is not dependent on the inlet radius. The approach was tested on reinforcements with fabric architectures which vary through-the-thickness direction, such as those in a spar cap of a wind turbine blade. The computational simulations of the flow-front progression through-the-thickness were consistent with experimental observations.





Author(s):  
Debabrata Adhikari ◽  
Suhasini Gururaja

Modeling resin flow for a Vacuum Assisted Resin Transfer Molding (VARTM) process involves developing an approach for coupled flow-compaction, porosity-permeability, resin-cure and stress-development phenomena. In the present work, a modified transient incompressible resin flow model has been developed for VARTM without considering the constant flow rate assumption. The use of High Permeability Medium (HPM) during VARTM results in a through-thickness flow in addition to in-plane flow developing due to the pressure gradient. Results have been validated with existing literature. Fill time comparisons for with and without HPM cases have been presented. Some preliminary results of 2D plane flow have also been obtained which show promise in replicating the physics of vacuum assisted resin infusion composite manufacturing process.



2016 ◽  
Vol 50 (29) ◽  
pp. 4171-4186 ◽  
Author(s):  
Bo Yang ◽  
Qian Tang ◽  
Shilong Wang ◽  
Tianguo Jin ◽  
Fengyang Bi

Resin infusion (RI) process has been widely used for manufacturing composite parts. The variation of preform thickness brings great difficulty to the three-dimensional simulation of the filling stage. To accurately simulate the preform thickness change and resin flow during resin infusion, precise preform compaction models and dynamically changing geometry models need to be adopted. At present, resin flow is usually considered as two-dimensional and simple compaction models are employed to simplify the simulation, which degrades the prediction accuracy seriously. In this paper, general equations to describe the resin flow in the changing thickness cavity are developed, and the viscoelastic model is adopted which can fully express the dynamic characteristics of the preform compaction. To avoid solving the coupled resin flow/preform deformation equations directly, the volume of fluid method and the dynamic mesh model are employed to implement the tracking of the flow front and updating of cavity geometry model. The resin storage and release induced by porosity variations are adjusted by a master-slave element method to ensure mass conservation. Two simulation examples are carried out to demonstrate the capability of the above approach. The applicability of the approach on arbitrary complex domains and sequential injection strategy is also verified.



1999 ◽  
Author(s):  
Pavel B. Nedanov ◽  
Suresh G. Advani ◽  
Shawn W. Walsh ◽  
William O. Ballata

Abstract VARTM and SCRIMP composite manufacturing processes use a highly permeable media to distribute the resin through the thickness of the composite. Hence, manufacturing simulations of resin flow in such processes requires reliable data for in-plane as well as transverse permeability. The goal of this study is to propose a method for simultaneous determination of the principal values of 3D-permeability tensor of fibrous reinforcements. The permeability components are calculated from experimental data, consisting of flow front position with time during resin impregnation in three dimensions from a radial source under constant pressure using the SMARTweave [Walsh (1993), Fink et al.(1995)] sensor system. Experimental results are compared with numerical simulation.



Author(s):  
I. Crivelli Visconti ◽  
M. Durante ◽  
A. Langella ◽  
U. Morano
Keyword(s):  


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