Investigation and multi-scale optimization design of woven composite cut-out structures

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Duc Hai Nguyen ◽  
Hu Wang ◽  
Fan Ye ◽  
Wei Hu
Keyword(s):  
Mechanical Properties ◽  
Composite Structures ◽  
Optimization Design ◽  
Material Behavior ◽  
Efficient Global Optimization ◽  
Support Vector ◽  
Woven Composite ◽  
Content Type ◽  
Multi Scale ◽  
Ply Orientation

Purpose The purpose of this paper is to investigate the mechanical properties’ behaviors of woven composite cut-out structures with specific parameters. Because of the complexity of micro-scale and meso-scale structure, it is difficult to accurately predict the mechanical material behavior of woven composites. Numerical simulations are increasingly necessary for the design and optimization of test procedures for composite structures made by the woven composite. The results of the proposed method are well satisfied with the results obtained from the experiment and other studies. Moreover, parametric studies on different plates based on the stacking sequences are investigated. Design/methodology/approach A multi-scale modeling approach is suggested. Back-propagation neural networks (BPNN), radial basis function (RBF) and least square support vector regression are integrated with efficient global optimization (EGO) to reduce the weight of assigned structure. Optimization results are verified by finite element analysis. Findings Compared with other similar studies, the advantage of the suggested strategy uses homogenized properties behaviors with more complex analysis of woven composite structures. According to investigation results, it can be found that 450/−450 ply-orientation is the best buckling load value for all the cut-out shape requirements. According to the optimal results, the BPNN-EGO is the best candidate for the EGO to optimize the woven composite structures. Originality/value A multi-scale approach is used to investigate the mechanical properties of a complex woven composite material architecture. Buckling of different cut-out shapes with the same area is surveyed. According to investigation, 45°/−45° ply-orientation is the best for all cut-out shapes. Different surrogate models are integrated in EGO for optimization. The BPNN surrogate model is the best choice for EGO to optimization difficult problems of woven composite materials.

Reliability-based design optimization of 3D orthogonal woven composite automobile shock tower

2021 ◽  
pp. 002199832110476
Author(s):  
Zhao Liu ◽  
Lei Zhang ◽  
Ping Zhu ◽  
Mushi Li
Keyword(s):  
Design Optimization ◽  
Composite Structures ◽  
Optimization Design ◽  
Optimization Procedure ◽  
Woven Composite ◽  
Reliability Based Design Optimization ◽  
Multi Scale ◽  
Reliability Based Design ◽  
Design Variables ◽  
3D Orthogonal Woven

Three-dimensional orthogonal woven composites are noted for their excellent mechanical properties and delamination resistance, so they are expected to have promising prospects in lightweight applications in the automobile industry. The multi-scale characteristics and inherent uncertainty of design variables pose great challenges to the optimization procedure for 3D orthogonal woven composite structures. This paper aims to propose a reliability-based design optimization method for guidance on the lightweight design of 3D orthogonal woven composite automobile shock tower, which includes design variables from material and structure. An analytical model was firstly set up to accurately predict the elastic and strength properties of composites. After that, a novel optimization procedure was established for the multi-scale reliability optimization design of composite shock tower, based on the combination of Monte Carlo reliability analysis method, Kriging surrogate model, and particle swarm optimization algorithm. According to the results, the optimized shock tower meets the requirements of structural performance and reliability, with a weight reduction of 37.83%.

Multi-scale finite element modeling of 3D printed structures subjected to mechanical loads

2018 ◽  
Vol 24 (1) ◽  
pp. 177-187 ◽  
Author(s):  
Dalia Calneryte ◽  
Rimantas Barauskas ◽  
Daiva Milasiene ◽  
Rytis Maskeliunas ◽  
Audrius Neciunas ◽  
...  
Keyword(s):  
Finite Element ◽  
Composite Structures ◽  
Computational Models ◽  
Three Dimensional ◽  
Structural Response ◽  
Content Type ◽  
Multi Scale ◽  
Macro Scale ◽  
Internal Constitution ◽  
3D Printed

Purpose The purpose of this paper is to investigate the influence of geometrical microstructure of items obtained by applying a three-dimensional (3D) printing technology on their mechanical strength. Design/methodology/approach Three-dimensional printed items (3DPI) are composite structures of complex internal constitution. The buildup of the finite element (FE) computational models of 3DPI is based on a multi-scale approach. At the micro-scale, the FE models of representative volume elements corresponding to different additive layer heights and different thicknesses of extruded fibers are investigated to obtain the equivalent non-linear nominal stress–strain curves. The obtained results are used for the creation of macro-scale FE models, which enable to simulate the overall structural response of 3D printed samples subjected to tensile and bending loads. Findings The validation of the models was performed by comparing the computed results against the experimental ones, where satisfactory agreement has been demonstrated within a marked range of thicknesses of additive layers. Certain inadequacies between computed against experimental results were observed in cases of thinnest and thickest additive layers. The principle explanation of the reasons of inadequacies takes into account the poorer quality of mutual adhesion in case of very thin extruded fibers and too-early solidification effect. Originality/value Flexural and tensile experiments are simulated by FE models that are created with consideration to microstructure of 3D printed samples.

Experiment-based validation and uncertainty quantification of coupled multi-scale plasticity models

2016 ◽  
Vol 12 (1) ◽  
pp. 151-176 ◽  
Author(s):  
Garrison Stevens ◽  
Sez Atamturktur ◽  
Ricardo Lebensohn ◽  
George Kaschner
Keyword(s):  
Coupled Model ◽  
Material Behavior ◽  
Radioactive Material ◽  
Material Structure ◽  
Coupled Models ◽  
Content Type ◽  
Strongly Coupled ◽  
Multi Scale ◽  
Macro Scale ◽  
Meso Scale

Purpose – Highly anisotropic zirconium is a material used in the cladding of nuclear fuel rods, ensuring containment of the radioactive material within. The complex material structure of anisotropic zirconium requires model developers to replicate not only the macro-scale stresses but also the meso-scale material behavior as the crystal structure evolves; leading to strongly coupled multi-scale plasticity models. Such strongly coupled models can be achieved through partitioned analysis techniques, which couple independently developed constituent models through an iterative exchange of inputs and outputs. Throughout this iterative process, biases, and uncertainties inherent within constituent model predictions are inevitably transferred between constituents either compensating for each other or accumulating during iterations. The paper aims to discuss these issues. Design/methodology/approach – A finite element model at the macro-scale is coupled in an iterative manner with a meso-scale viscoplastic self-consistent model, where the former supplies the stress input and latter represents the changing material properties. The authors present a systematic framework for experiment-based validation taking advantage of both separate-effect experiments conducted within each constituent’s domain to calibrate the constituents in their respective scales and integral-effect experiments executed within the coupled domain to test the validity of the coupled system. Findings – This framework developed is shown to improve predictive capability of a multi-scale plasticity model of highly anisotropic zirconium. Originality/value – For multi-scale models to be implemented to support high-consequence decisions, such as the containment of radioactive material, this transfer of biases and uncertainties must be evaluated to ensure accuracy of the predictions of the coupled model. This framework takes advantage of the transparency of partitioned analysis to reduce the accumulation of errors and uncertainties.

Multi‐scale modeling of heterogeneous structures with inelastic constitutive behaviour

2005 ◽  
Vol 22 (5/6) ◽  
pp. 664-683 ◽  
Author(s):  
Damijan Markovic ◽  
Rainer Niekamp ◽  
Adnan Ibrahimbegović ◽  
Hermann G. Matthies ◽  
Robert L. Taylor
Keyword(s):  
Composite Structures ◽  
Component Technology ◽  
Theoretical Formulation ◽  
Computational Framework ◽  
Content Type ◽  
Multi Scale ◽  
Scale Modeling ◽  
Heterogeneous Structures ◽  
Recent Developments ◽  
Inelastic Behaviour

PurposeTo provide a computational strategy for highly accurate analyses of non‐linear inelastic behaviour for heterogeneous structures in civil and mechanical engineering applicationsDesign/methodology/approachAdapts recent developments on mathematical formulations of multi‐scale problems to the recently developed component technology based on C++ generic templates programming.FindingsProvides the understanding how theoretical hypotheses, concerning essentially the multi‐scale interface conditions, affect the computational precision of the strategy.Practical implicationsThe present approach allows a very precise modelling of multi‐scale aspects in structural mechanics problems and can play an essential tool in searching for an optimal structural design.Originality/valueProvides all the ingredients for constructing an efficient multi‐scale computational framework, from the theoretical formulation to the implementation for parallel computing. It is addressed to researchers and engineers analysing composite structures under extreme loading.

Application of ultrasonic peening during DMLS production of 316L stainless steel and its effect on material behavior

2017 ◽  
Vol 23 (6) ◽  
pp. 1185-1194 ◽  
Author(s):  
Joshua Gale ◽  
Ajit Achuhan
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
316L Stainless Steel ◽  
Tensile Tests ◽  
Material Behavior ◽  
Uniaxial Tensile ◽  
Layer By Layer ◽  
Content Type ◽  
Ultrasonic Peening ◽  
Am Processes

Purpose Additive manufacturing (AM) processes involve a layer-by-layer sintering of metallic powders to produce fully functional three-dimensional parts. This layer-by-layer building process provides a unique opportunity to enhance mechanical properties by applying treatments that previously were possible only on the surface in traditional manufacturing techniques. The purpose of the study is to examine the effect of ultrasonic peening (UP) applied during a layer-by-layer direct metal laser sintering (DMLS) fabrication of 316L stainless steel on its mechanical properties and microstructure. Design/methodology/approach Uniaxial tensile tests were performed at 1.27 mm/s to determine the effect of UP treatment on the average global behavior of a 316L part, whereas hardness measurements using nanoindentation were performed to determine the modification of local mechanical properties. Compressive buckling tests at a loading rate of 3 mm/min were performed on sample coupons with a large aspect ratio to evaluate the effect of UP on any potential delamination of DMLS layers. Techniques such as optical and scanning electron microscopy (SEM) imaging were utilized to determine the effect of UP on the microstructure. Findings Overall, significant modification in mechanical properties such as hardness and yield strength, along with microstructure, was observed. Large increases in both the average global and local mechanical properties, as well as a disruption in the columnar grain microstructure, was observed in DMLS parts treated with UP treatment. Originality/value Results indicate an opportunity for UP to be used as an in-situ process during AM processes for dynamically altering the mechanical behavior, microstructure, and distortion due to residual stress formation, in a tunable fashion.

Multi-scale numerical simulation analysis for influence of combined leaching and frost deteriorations on mechanical properties of concrete

2016 ◽  
Vol 12 (4) ◽  
pp. 648-671 ◽  
Author(s):  
Jiang Hu
Keyword(s):  
Mechanical Properties ◽  
Numerical Simulation ◽  
Frost Damage ◽  
Hydraulic Pressure ◽  
Structural Level ◽  
Content Type ◽  
Calcium Leaching ◽  
Multi Scale ◽  
Random Aggregate

Purpose The multi-scale numerical simulation method, able to represent the complexity of the random structures and capture phase degradation, is an effective way to investigate the long-term behavior of concrete in service and bridges the gap between research on the material and on the structural level. However, the combined chemical-physical deterioration mechanisms of concrete remain a challenging task. The purpose of this paper is to investigate the degradation mechanism of concrete at the waterline in cold regions induced by combined calcium leaching and frost damage. Design/methodology/approach With the help of the NIST’s three-dimensional (3D) hydration model and the random aggregate model, realistic 3D representative volume elements (RVEs) of concrete at the micro-, the meso-, and the macro-scales can be reconstructed. The boundary problem method is introduced to compute the homogenized mechanical properties for both sound and damaged RVEs. According to the damage characteristics, the staggering method including a random dissolution model and a thermo-mechanical coupling model is developed to simulate the synergy deterioration effects of interacted calcium leaching and frost attacks. The coupled damage procedure for the frost damage process is based on the hydraulic pressure theory and the ice lens growth theory considering the relationship between the frozen temperature and the radius of the capillary pore. Finally, regarding calcium leaching as the leading role in actual engineering, the numerical methodology for combined leaching and frost damage on concrete property is proposed using a successive multi-scale method. Findings On the basis of available experimental data, this methodology is employed to explore the deterioration process. The results agree with the experimental ones to some extent, chemical leaching leads to the nucleation of some micro-cracks (i.e. damage), and consequently, to the decrease of the frost resistance. Originality/value It is demonstrated that the multi-scale numerical methodology can capture potential aging and deterioration evolution processes, and can give an insight into the macroscopic property degradation of concrete under long-term aggressive conditions.

scholarly journals Anti-Inflammatory Properties of Injectable Betamethasone-Loaded Tyramine-Modified Gellan Gum/Silk Fibroin Hydrogels

Biomolecules ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1456
Author(s):  
Isabel Matos Oliveira ◽  
Cristiana Gonçalves ◽  
Myeong Eun Shin ◽  
Sumi Lee ◽  
Rui Luis Reis ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Mechanical Properties ◽  
Silk Fibroin ◽  
Therapeutic Efficacy ◽  
Composite Structures ◽  
Gelation Time ◽  
Polymeric Materials ◽  
Gellan Gum ◽  
Traditional Use

Rheumatoid arthritis is a rheumatic disease for which a healing treatment does not presently exist. Silk fibroin has been extensively studied for use in drug delivery systems due to its uniqueness, versatility and strong clinical track record in medicine. However, in general, natural polymeric materials are not mechanically stable enough, and have high rates of biodegradation. Thus, synthetic materials such as gellan gum can be used to produce composite structures with biological signals to promote tissue-specific interactions while providing the desired mechanical properties. In this work, we aimed to produce hydrogels of tyramine-modified gellan gum with silk fibroin (Ty–GG/SF) via horseradish peroxidase (HRP), with encapsulated betamethasone, to improve the biocompatibility and mechanical properties, and further increase therapeutic efficacy to treat rheumatoid arthritis (RA). The Ty–GG/SF hydrogels presented a β-sheet secondary structure, with gelation time around 2–5 min, good resistance to enzymatic degradation, a suitable injectability profile, viscoelastic capacity with a significant solid component and a betamethasone-controlled release profile over time. In vitro studies showed that Ty–GG/SF hydrogels did not produce a deleterious effect on cellular metabolic activity, morphology or proliferation. Furthermore, Ty–GG/SF hydrogels with encapsulated betamethasone revealed greater therapeutic efficacy than the drug applied alone. Therefore, this strategy can provide an improvement in therapeutic efficacy when compared to the traditional use of drugs for the treatment of rheumatoid arthritis.

Sign in / Sign up

Export Citation Format

Share Document