Integrated Prediction of Mechanical Behavior for the Non-Aligned Fiber Composites With Experimental Validation

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Bingyun Jiang ◽  
Chen Tian
Keyword(s):  
Injection Molding ◽  
Fiber Orientation ◽  
Mean Field ◽  
Transversely Isotropic ◽  
Integrated Approach ◽  
Mapping Method ◽  
Design Guidelines ◽  
Plastic Behavior ◽  
Micro Computed Tomography ◽  
Orientation Tensor

Abstract This paper aims to present an integrated multi-scale method for predicting the anisotropic and nonlinear elasto-plastic behavior of short glass fiber-reinforced polymer (GFRP) materials typically produced by injection molding. The proposed method combines injection molding and microstructure together, with considering the nonaligned fibers and their corresponding anisotropy, to semi-analytically estimate the local effective mechanical properties at every point of GFRP. Micro-computed tomography measurement and injection molding simulation are used to obtain the fiber orientation tensor. The two-step mean-field homogenization method is applied to calculate the mechanical behaviors of the PA66GF30 GFRP with distributed-orientation fibers based on the fiber orientation tensor. Reverse engineering is used to obtain the optimized parameters of J2-plasticity and Tsai-Hill three-dimensional transversely isotropic stain-based failure criterion. Moreover, the integral mapping method can complete the transformation of the fiber orientation tensor from injection simulation to structure simulation model. The proposed integrated approach with the optimized parameters is verified by predicting the ring samples’ behavior from injection plates. The results from this investigation are expected to provide some design guidelines for GFRP composites.

scholarly journals Investigation on the Fiber Orientation Distributions and Their Influence on the Mechanical Property of the Co-Injection Molding Products

Polymers ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 24
Author(s):  
Chao-Tsai Huang ◽  
Xuan-Wei Chen ◽  
Wei-Wen Fu
Keyword(s):  
Injection Molding ◽  
Tensile Properties ◽  
Fiber Orientation ◽  
Flow Direction ◽  
Rapid Development ◽  
Injection System ◽  
Single Shot ◽  
Fiber Morphology ◽  
Orientation Tensor ◽  
Orientation Distributions

In recent years, due to the rapid development of industrial lightweight technology, composite materials based on fiber reinforced plastics (FRP) have been widely used in the industry. However, the environmental impact of the FRPs is higher each year. To overcome this impact, co-injection molding could be one of the good solutions. But how to make the suitable control on the skin/core ratio and how to manage the glass fiber orientation features are still significant challenges. In this study, we have applied both computer-aided engineering (CAE) simulation and experimental methods to investigate the fiber feature in a co-injection system. Specifically, the fiber orientation distributions and their influence on the tensile properties for the single-shot and co-injection molding have been discovered. Results show that based on the 60:40 of skin/core ratio and same materials, the tensile properties of the co-injection system, including tensile stress and modulus, are a little weaker than that of the single-shot system. This is due to the overall fiber orientation tensor at flow direction (A11) of the co-injection system being lower than that of the single-shot system. Moreover, to discover and verify the influence of the fiber orientation features, the fiber orientation distributions (FOD) of both the co-injection and single-shot systems have been observed using micro-computerized tomography (μ-CT) technology to scan the internal structures. The scanned images were further utilizing Avizo software to perform image analyses to rebuild the fiber structure. Specifically, the fiber orientation tensor at flow direction (A11) of the co-injection system is about 89% of that of the single-shot system in the testing conditions. This is because the co-injection part has lower tensile properties. Furthermore, the difference of the fiber orientation tensor at flow direction (A11) between the co-injection and the single-shot systems is further verified based on the fiber morphology of the μ-CT scanned image. The observed result is consistent with that of the FOD estimation using μ-CT scan plus image analysis.

scholarly journals Variety of fiber orientation tensors

2021 ◽  
pp. 108128652110576
Author(s):  
Julian Karl Bauer ◽  
Thomas Böhlke
Keyword(s):  
Fiber Orientation ◽  
Mechanical Response ◽  
Transversely Isotropic ◽  
Orientation Tensor ◽  
Isotropic State ◽  
Orientation Tensors ◽  
Linear Invariant ◽  
Parameter Ranges ◽  
Independent Parameters

Fiber orientation tensors are established descriptors of fiber orientation states in (thermo-)mechanical material models for fiber-reinforced composites. In this paper, the variety of fourth-order orientation tensors is analyzed and specified by parameterizations and admissible parameter ranges. The combination of parameterizations and admissible parameter ranges allows for studies on the mechanical response of different fiber architectures. Linear invariant decomposition with focus on index symmetry leads to a novel compact hierarchical parameterization, which highlights the central role of the isotropic state. Deviation from the isotropic state is given by a triclinic harmonic tensor with simplified structure in the orientation coordinate system, which is spanned by the second-order orientation tensor. Material symmetries reduce the number of independent parameters. The requirement of positive-semi-definiteness defines admissible ranges of independent parameters. Admissible parameter ranges for transversely isotropic and planar cases are given in a compact closed form and the orthotropic variety is visualized and discussed in detail. Sets of discrete unit vectors, leading to selected orientation states, are given.

scholarly journals Modeling and Simulation of Fiber Orientation in Injection Molding of Polymer Composites

2011 ◽  
Vol 2011 ◽  
pp. 1-14 ◽  
Author(s):  
Jang Min Park ◽  
Seong Jin Park
Keyword(s):  
Finite Element ◽  
Injection Molding ◽  
Fiber Orientation ◽  
Flow Model ◽  
Three Dimensional ◽  
Coupled Analysis ◽  
Injection Molding Process ◽  
Molding Process ◽  
Orientation Tensor ◽  
Closure Approximations

We review the fundamental modeling and numerical simulation for a prediction of fiber orientation during injection molding process of polymer composite. In general, the simulation of fiber orientation involves coupled analysis of flow, temperature, moving free surface, and fiber kinematics. For the governing equation of the flow, Hele-Shaw flow model along with the generalized Newtonian constitutive model has been widely used. The kinematics of a group of fibers is described in terms of the second-order fiber orientation tensor. Folgar-Tucker model and recent fiber kinematics models such as a slow orientation model are discussed. Also various closure approximations are reviewed. Therefore, the coupled numerical methods are needed due to the above complex problems. We review several well-established methods such as a finite-element/finite-different hybrid scheme for Hele-Shaw flow model and a finite element method for a general three-dimensional flow model.

scholarly journals Backward-forward linear-quadratic mean-field Stackelberg games

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Kehan Si ◽  
Zhen Wu
Keyword(s):  
Large Population ◽  
Consistency Condition ◽  
Market Price ◽  
Mean Field ◽  
Mapping Method ◽  
Open Loop ◽  
Stackelberg Games ◽  
Linear Quadratic ◽  
Population System ◽  
The Cost

AbstractThis paper studies a controlled backward-forward linear-quadratic-Gaussian (LQG) large population system in Stackelberg games. The leader agent is of backward state and follower agents are of forward state. The leader agent is dominating as its state enters those of follower agents. On the other hand, the state-average of all follower agents affects the cost functional of the leader agent. In reality, the leader and the followers may represent two typical types of participants involved in market price formation: the supplier and producers. This differs from standard MFG literature and is mainly due to the Stackelberg structure here. By variational analysis, the consistency condition system can be represented by some fully-coupled backward-forward stochastic differential equations (BFSDEs) with high dimensional block structure in an open-loop sense. Next, we discuss the well-posedness of such a BFSDE system by virtue of the contraction mapping method. Consequently, we obtain the decentralized strategies for the leader and follower agents which are proved to satisfy the ε-Nash equilibrium property.

scholarly journals Warpage Reduction of Glass Fiber Reinforced Plastic Using Microcellular Foaming Process Applied Injection Molding

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 360 ◽  
Author(s):  
Hyun Kim ◽  
Joo Sohn ◽  
Youngjae Ryu ◽  
Shin Kim ◽  
Sung Cha
Keyword(s):  
Injection Molding ◽  
Glass Fiber ◽  
Fiber Orientation ◽  
Mechanical And Thermal Properties ◽  
Micro Ct ◽  
Fiber Reinforced ◽  
Foaming Process ◽  
Microcellular Foaming ◽  
Glass Fiber Reinforced ◽  
The Impact

This study analyzes the fundamental principles and characteristics of the microcellular foaming process (MCP) to minimize warpage in glass fiber reinforced polymer (GFRP), which is typically worse than that of a solid polymer. In order to confirm the tendency for warpage and the improvement of this phenomenon according to the glass fiber content (GFC), two factors associated with the reduction of the shrinkage difference and the non-directionalized fiber orientation were set as variables. The shrinkage was measured in the flow direction and transverse direction, and it was confirmed that the shrinkage difference between these two directions is the cause of warpage of GFRP specimens. In addition, by applying the MCP to injection molding, it was confirmed that warpage was improved by reducing the shrinkage difference. To further confirm these results, the effects of cell formation on shrinkage and fiber orientation were investigated using scanning electron microscopy, micro-CT observation, and cell morphology analysis. The micro-CT observations revealed that the fiber orientation was non-directional for the MCP. Moreover, it was determined that the mechanical and thermal properties were improved, based on measurements of the impact strength, tensile strength, flexural strength, and deflection temperature for the MCP.

Fiber orientation in divergent/convergent flows in expansion and compression injection molding

2006 ◽  
Vol 27 (5) ◽  
pp. 539-551 ◽  
Author(s):  
Cristina A. Silva ◽  
Júlio C. Viana ◽  
Ferrie W.J. van Hattum ◽  
António M. Cunha
Keyword(s):  
Injection Molding ◽  
Fiber Orientation

scholarly journals Fiber orientation and material properties analysis in injection molding.

1991 ◽  
Vol 48 (3) ◽  
pp. 151-157 ◽  
Author(s):  
Takaaki MATSUOKA ◽  
Yoshinori INOUE ◽  
Jun-ichi TAKABATAKE
Keyword(s):  
Injection Molding ◽  
Material Properties ◽  
Fiber Orientation

Optimization of fiber prediction model coefficients in injection molding simulation based on micro computed tomography

2018 ◽  
Vol 59 (s2) ◽  
pp. E152-E160 ◽  
Author(s):  
Matthias Morak ◽  
Daniel Tscharnuter ◽  
Thomas Lucyshyn ◽  
Wolfram Hahn ◽  
Michael Göttlinger ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Injection Molding ◽  
Prediction Model ◽  
Micro Computed Tomography ◽  
Simulation Based ◽  
Injection Molding Simulation

Tribology study of hydroxyapatite (HAp) scaffold blended single based binder via rheology and mechanical properties

2017 ◽  
Vol 69 (3) ◽  
pp. 414-419
Author(s):  
Mimi Azlina Abu Bakar ◽  
Siti Norazlini Abd Aziz ◽  
Muhammad Hussain Ismail
Keyword(s):  
Mechanical Properties ◽  
Injection Molding ◽  
Palm Stearin ◽  
Polymeric Materials ◽  
High Energy ◽  
Single Step ◽  
Injection Molding Process ◽  
Plastic Behavior ◽  
Molding Process ◽  
Content Type

Purpose This paper aims to investigate the vital characteristic of an innovative ceramic injection molding (CIM) process for orthopedic application with controlled porosity and improved tribological and mechanical properties which were affected by complex tribological interactions, whether lubricated like hip implants and other artificial prostheses. The main objective is to maximize the usage of palm stearin as a single based binder as the function of flow properties during injection molding process. Design/methodology/approach The binder used in this present study consists of 100 per cent palm stearin manufactured by Kempas Oil Sdn Bhd and supplied by Vistec Technology Sdn Bhd. The feedstock was prepared by using a Z-blade mixer (Thermo Haake Rheomix OS) and Brabender mixer model R2400. The feedstock prepared was injection molded using a manually operated vertical benchtop machine with an average pressure of about 5-7 bars. The firing step included the temporary holds at intermediate temperatures to burn out organic binders. At this stage, the green molded specimen was de-bound using a single-step wick-debinding method. Findings The maximum content of ceramic material is applied to investigate the efficiencies of net formulation that can be achieved by ceramic materials. The longer the viscosity will change with shear rate, the higher the value of n obtained instead. From the slope of the curves obtained in Figure 3, the value of n for the feedstock was determined to be less than 1, which indicates a pseudoplastic behavior and suitability for the molding process. Moreover, high shear sensitivity is important in producing complex and intrinsic specimens which are leading products in the CIM industry. Originality/value The feedstock containing HAp powder and palm stearin binder was successfully prepared at very low temperature of 70°C, which promoting a required pseudo-plastic behavior during rheological test. The single binder palm stearin should be optimized in other research works carried out, as palm stearin is most preferred compared to other polymeric materials that provided high energy consumption when subjected to the sintering process. Besides the binder is widely available in Malaysia, low cost and harmless effect during debinding process.

Sign in / Sign up

Export Citation Format

Share Document