An Orthotropic Integrated Flow-Stress Model for Process Simulation of Composite Materials—Part I: Two-Phase Systems

Author(s):  
Sina Amini Niaki ◽  
Alireza Forghani ◽  
Reza Vaziri ◽  
Anoush Poursartip

An integrated flow-stress (IFS) model provides a seamless and mechanistic connection between the two distinct regimes during the manufacturing process of composite materials, namely, fluid flow in the pregelation stage of the thermoset resin and stress development in the composite when it acts as a solid material. In this two-part paper, the two- and three-phase isotropic IFS models previously developed by the authors are extended to the general case of composite materials with orthotropic constituents. Part I presents the two-phase, fluid-solid, orthotropic model formulation for the case where the fluid phase solidifies during the course of curing. Part II extends the orthotropic formulation to a three-phase model that includes a gas phase as the third constituent of the composite material system. A broader definition of material properties in poroelasticity formulation is adopted in the development of the general orthotropic formulation. The model is implemented in a two-dimensional (2D) plane strain u-v-P finite element (FE) code and its capability in predicting the flow-compaction behavior and stress development is demonstrated through application to a case study involving an L-shaped unidirectional laminate undergoing curing on a conforming convex tool. Comparison of the results with those obtained from sole modeling of the stress development reveals the importance of capturing the simultaneous and interactive effect of the mechanisms involved during the entire process cycle using an IFS modeling approach presented in this paper.

Author(s):  
Sina Amini Niaki ◽  
Alireza Forghani ◽  
Reza Vaziri ◽  
Anoush Poursartip

In this paper, the two-phase orthotropic integrated flow-stress (IFS) process model presented in Part I is extended to a three-phase model where the third-phase accounts for the presence of gas in the composite material system. The gas flow and its compressibility are taken into account, while the seamless transformation of the resin material from its initially liquid stage to a cured solid material is incorporated within the previously developed IFS framework. A three-phase orthotropic flow model is employed to describe the behavior of the composite material during the pregelation stage of the process cycle which transforms continuously to a solid mechanics model using a stepwise three-phase micromechanics. The model is implemented in a u–v–P plane strain finite element code similar to that presented in Part I but with extended degrees-of-freedom accounting for the velocity and pressure of the gas phase. The numerical model is applied to the debulking and curing process of an L-shaped unidirectional composite laminate. Performance of the model is assessed through evaluating the process-induced deformations and residual porosity distribution over the spatial domain of the laminate.


2013 ◽  
Vol 29 (4) ◽  
pp. 675-683 ◽  
Author(s):  
P.-J. Lin

ABSTRACTThis paper proposes a three-phase constitutive model for estimating the elastic moduli and strength of granular composite. The three-phase granular composite material containing aggregate (inclusion), matrix, and aggregate/matrix interface were investigated in this study. It was observed that significant improvement in predictive capability for three-phase granular composite materials can be achieved by using the proposed method. By using micromechanics and adopting the double-inclusion concept initiated by Hori and Nemat-Nasser and the two-phase model introduced by Yang et al.; the predicted elastic moduli for three-phase granular composite materials were evaluated. Moreover, analytical formulas were obtained to predict the strengths of three-phase granular composite materials. The potential of the proposed framework was also explored by comparing the analytical predictions in this study with other analytical methods as well as experimental data of other studies.


2009 ◽  
Vol 41 (1) ◽  
pp. 3-10 ◽  
Author(s):  
A.F. Lisovsky

Thermodynamic functions have been derived that describe the processes of nanoparticle consolidation in solid-mobile phase two- and three-phase dispersed systems. An expression for the shrinkage pressure in a two-phase dispersed system has been deduced, which allows one to calculate stresses generating in the bulk of heterophase composite materials in the course of the nanoparticle consolidation. On the strength of these thermodynamic functions criteria have been suggested that allow one to predict the structure of a nanocomposite material.


Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 650
Author(s):  
Ziwei Li ◽  
Chiara Confalonieri ◽  
Elisabetta Gariboldi

Evaluation of thermal conductivity of composite materials is extremely important to control material performance and stability in thermal applications as well as to study transport phenomena. In this paper, numerical simulation of effective thermal conductivity of Al-Sn miscibility gap alloys is validated with experimental results. Lattice Monte-Carlo (LMC) method is applied to two-phase and three-phase materials, allowing to estimate effective thermal conductivity from micrographs and individual phase properties. Numerical results are compared with literature data for cast Al-Sn alloys for the two-phase model and with a specifically produced powder metallurgy Al-10vol%Sn, tested using laser flash analysis, for a three-phase simulation. A good agreement between numerical and experimental data was observed. Moreover, LMC simulations confirmed the effect of phase morphology as well as actual phase composition on thermal conductivity of composite materials.


Author(s):  
Bakkali Abderrahmane ◽  
Azrar Lahcen ◽  
Abdulmalik Ali Aljinaidi

The differential scheme is extended to predict the effective properties of multiphase magnetoelectroelastic composite materials. The prediction of effective properties is done gradually by adding a series of incremental additions of a small volume of particulate phase materials to an initial material (matrix phase). The construction process is compatible with high volume concentration of inclusion. A system of coupled differential equations is formulated and its numerical solution leads to effective properties of reinforced magnetoelectroelastic composites. For the numerical results, two-phase and three-phase magnetoelectroelastic composites are considered. The effective properties are presented as function of volume fractions and shapes of inclusions and compared with predictions based on the Mori–Tanaka and incremental self-consistent models.


Author(s):  
Guntis Diļevs ◽  
Edgars Jakobsons

The generated power of multipole induction generator with secondary winding on the statorThis paper posses the construction of induction generator, which has the ability to operate at a low rotation speed. This generator can be applied for directly driven turbine without using the gearbox. The generator is multi pole with all of the windings placed on the stator. Rotor is tooth-like and has no windings on it. Primary winding is three phase, secondary winding is two phase.


2020 ◽  
Author(s):  
Ziya Özkan ◽  
Ahmet Masum Hava

In three-phase three-wire (3P3W) voltage-source converter (VSC) systems, utilization of filter inductors with deep saturation characteristics is often advantageous due to the improved size, cost, and efficiency. However, with the use of conventional synchronous frame current control (CSCC) methods, the inductor saturation results in significant dynamic performance loss and poor steady-state current waveform quality. This paper proposes an inverse dynamic model based compensation (IDMBC) method to overcome these performance issues. Accordingly, a review of inductor saturation and core materials is performed, and the motivation on the use of saturable inductors is clarified. Then, two-phase exact modelling of the 3P3W VSC control system is obtained and the drawbacks of CSCC have been demonstrated analytically. Based on the exact modelling, the inverse system dynamic model of the nonlinear system is obtained and employed such that the nonlinear plant is converted to a fictitious linear inductor system for linear current regulators to perform satisfactorily.


1997 ◽  
Vol 35 (7) ◽  
pp. 139-145 ◽  
Author(s):  
Jiann-Yuan Ding ◽  
Shian-Chee Wu

The objective of this study is to quantify the effects of humic acid solution infiltration on the transport of organochlorine pesticides (OCPs) in soil columns using a three-phase transport model. From experimental results, it is found that the dissolved organic carbon enhances the transport of OCPs in the soil columns. In the OCPs-only column, the concentration profiles of OCPs can be simulated well using a two-phase transport model with numerical method or analytical solution. In the OCPs-DOC column, the migrations of aldrin, DDT and its daughter compounds are faster than those in the OCPs-only column. The simulation with the three-phase model is more accurate than that with the two-phase model. In addition, significant decrease of the fluid pore velocities of the OCPs-DOC column was found. When DOC leachate is applied for remediation of soil or groundwater pollution, the decrease of mean pore velocities will be a crucial affecting factor.


Author(s):  
Jingwen Chen ◽  
Hongshe Dang

Background: Traditional thyristor-based three-phase soft starters of induction motor often suffer from high starting current and heavy harmonics. Moreover, both the trigger pulse generation and driving circuit design are usually complicated. Methods: To address these issues, we propose a novel soft starter structure using fully controlled IGBTs in this paper. Compared to approaches of traditional design, this structure only uses twophase as the input, and each phase is controlled by a power module that is composed of one IGBT and four diodes. Results: Consequently, both driving circuit and control design are greatly simplified due to the requirement of fewer controlled power semiconductor switches, which leads to the reduction of the total cost. Conclusion: Both Matlab/Simulink simulation results and experimental results on a prototype demonstrate that the proposed soft starter can achieve better performances than traditional thyristorbased soft starters for Starting Current (RMS) and harmonics.


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