scholarly journals Simulation Study of Adhesive Material for Sandwich Panel under Edgewise Compression Condition

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1391
Author(s):  
Lanxin Jiang ◽  
Bing Yang ◽  
Shoune Xiao ◽  
Guangwu Yang ◽  
Tao Zhu ◽  
...  
Keyword(s):  
Peak Load ◽  
Adhesive Layer ◽  
Material Model ◽  
Simulation Method ◽  
Adhesive Material ◽  
Element Size ◽  
Influence Degree ◽  
Aluminum Alloy Panels ◽  
Theoretical Results ◽  
Compression Condition

In order to study the interfacial adhesive material simulation method of a sandwich structure with aluminum alloy panels and a low-density foam core under edgewise compression condition, two finite element models were defined using material model no. 185 (MAT 185) adhesive element and tiebreak contact, respectively, by LS-DYNA. Under the conditions of different loading rates, and element sizes, the effects of peak load, energy absorption, failure mode of adhesive layer and the influence degree of the changing condition on the calculated results were compared between the two models, and then compared with the experiment results and theoretical results. The higher the loading rate was, or the smaller the element size was, the higher the peak load was. The simulation results obtained using MAT 185 were closer to the experimental results under the edgewise compression condition.

Combination of Support Vector Machine and K-Fold cross-validation for prediction of long-term degradation of the compressive strength of marine concrete

2018 ◽  
Vol 1 (1) ◽  
pp. 120-130 ◽  
Author(s):  
Chunxiang Qian ◽  
Wence Kang ◽  
Hao Ling ◽  
Hua Dong ◽  
Chengyao Liang ◽  
...  
Keyword(s):  
Support Vector Machine ◽  
Environmental Factors ◽  
Cross Validation ◽  
Concrete Strength ◽  
Simulation Method ◽  
Support Vector ◽  
Svm Model ◽  
Artificial Neural Network Ann ◽  
Influence Degree ◽  
Fold Cross Validation

Support Vector Machine (SVM) model optimized by K-Fold cross-validation was built to predict and evaluate the degradation of concrete strength in a complicated marine environment. Meanwhile, several mathematical models, such as Artificial Neural Network (ANN) and Decision Tree (DT), were also built and compared with SVM to determine which one could make the most accurate predictions. The material factors and environmental factors that influence the results were considered. The materials factors mainly involved the original concrete strength, the amount of cement replaced by fly ash and slag. The environmental factors consisted of the concentration of Mg2+, SO42-, Cl-, temperature and exposing time. It was concluded from the prediction results that the optimized SVM model appeared to perform better than other models in predicting the concrete strength. Based on SVM model, a simulation method of variables limitation was used to determine the sensitivity of various factors and the influence degree of these factors on the degradation of concrete strength.

scholarly journals Attenuation of waves in a viscoelastic peridynamic medium

2019 ◽  
Vol 24 (11) ◽  
pp. 3597-3613 ◽  
Author(s):  
S. A. Silling
Keyword(s):  
Attenuation Coefficient ◽  
Material Properties ◽  
Cutoff Frequency ◽  
Material Model ◽  
One Dimensional ◽  
Spatial Nonlocality ◽  
Dissipative Material ◽  
The Time Domain ◽  
The Relationship ◽  
Theoretical Results

The effect of spatial nonlocality on the decay of waves in a dissipative material is investigated. The propagation and decay of waves in a one-dimensional, viscoelastic peridynamic medium is analyzed. Both the elastic and damping terms in the material model are nonlocal. Waves produced by a source with constant amplitude applied at one end of a semi-infinite bar decay exponentially with distance from the source. The model predicts a cutoff frequency that is influenced by the nonlocal parameters. A method for computing the attenuation coefficient explicitly as a function of material properties and source frequency is presented. The theoretical results are compared with direct numerical simulations in the time domain. The relationship between the attenuation coefficient and the group velocity is derived. It is shown that in the limit of long waves (or small peridynamic horizon), Stokes’ law of sound attenuation is recovered.

Investigation on the Modeling of Rotor Axial Displacement Fault Diagnosis and Prognosis for Centrifugal Compressor

2010 ◽  
Vol 139-141 ◽  
pp. 2542-2545 ◽  
Author(s):  
Wei Min Wang ◽  
Zheng Qiu Xin ◽  
Wei Zheng An
Keyword(s):  
Fault Diagnosis ◽  
Centrifugal Compressor ◽  
Mechanical Performance ◽  
Plastic Material ◽  
Material Model ◽  
Simulation Method ◽  
Axial Displacement ◽  
Elastic Model ◽  
Displacement Curve ◽  
Fault Diagnosis And Prognosis

In this paper, a modeling about centrifugal compressor axial displacement fault diagnosis is proposed through investigating on the mechanical performance and failure mode of thrust bearing as well as the characteristics of axial displacement fault. In this paper, result of experimental studying of the force-displacement curve of rotor at different speed is presented. Numerical simulation method is used to predict the curve in diagnosis model. By comprising the experimental and numerical result, it can be seen that Finite Element Method(FEM) elastic-perfectly plastic material model can get more precise result than linear elastic model and Computational Fluid Dynamics(CFD) method provide a new insight to investigation the physics based diagnosis method. Result of the paper provides the foundation of axial displacement fault self-recovery.

scholarly journals Experimental and Numerical Investigations of High-Speed Projectile Impacts on 7075-T651 Aluminum Plates

Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2736 ◽  
Author(s):  
Jae-Wook Jung ◽  
Sang Eon Lee ◽  
Jung-Wuk Hong
Keyword(s):  
High Speed ◽  
High Strain ◽  
Damage Model ◽  
Computational Cost ◽  
Material Model ◽  
Constitutive Relationship ◽  
Mesh Dependency ◽  
Element Size ◽  
Aluminum Plates ◽  
The Relationship

Simulation of the material failure under high strain rate conditions is one of the most difficult problems in the finite element analyses, and many researchers have tried to understand and reproduce dynamic material fracture. In this study, we investigate a failure criterion that minimizes the mesh dependency at high strain rates and incorporates the criterion into the Johnson-Cook constitutive relationship by developing a user-defined material model. Impact tests were performed using a gas-gun system in order to investigate the response of the 7075-T651 aluminum plate in high-speed collision. On the other hand, numerical simulations are carried out by considering various element sizes and the relationship between element size and failure strain is inversely obtained using numerical results. By accommodating the relationship into the damage model and implementing in the user-defined material model, mesh dependency is significantly reduced, and sufficient accuracy is achieved with alleviated computational cost than the existing damage model. This study suggests an element size-dependent damage criterion that is applicable for impact simulation and it is expected that the criterion is useful to obtain accurate impact responses with a small computational cost.

scholarly journals Mechanical properties of Methacrylic Plexus MA300 adhesive material determined in tensile test and butt joints of aluminum thick plates

2019 ◽  
Vol 290 ◽  
pp. 01007
Author(s):  
Paweł Maćkowiak ◽  
Dominika Płaczek ◽  
Agnieszka Sołtysiak
Keyword(s):  
Mechanical Properties ◽  
Cross Section ◽  
Adhesive Layer ◽  
Butt Joint ◽  
Adhesive Joints ◽  
Structural Components ◽  
Butt Joints ◽  
Adhesive Material ◽  
Thick Plates ◽  
Overlap Joint

Adhesive joints are an alternative method of joining elements. New adhesives achieve cohesion and adhesion strength comparable with plastics used for structural components and coatings. Bonding is faster, simpler and cheaper. For this reason, adhesive joints are increasingly replacing other types of connections. Tests show that the material properties in the cast adhesive specimens differ from the ones determined in the joint. Adhesive producers most often describe the strength of the overlap joint tested in accordance with ASTM D1002. Strength, modulus of elasticity and elongation to break tested in accordance with ASTM D638 are reported less frequently. The article presents a method for determining the mechanical properties of the adhesive in a butt joint and differences in the determined values in relation to the cast specimens on the example of methacrylic adhesive Plexus MA300. The tests were carried out for joining aluminium rod with a square cross-section of 15 mm x 15 mm and adhesive layer thickness of approximately 1 mm. The fractures of cast specimens and butt joints were analyzed.

scholarly journals Bio-Inspired 3D Infill Patterns for Additive Manufacturing and Structural Applications

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 499 ◽  
Author(s):  
Jan Podroužek ◽  
Marco Marcon ◽  
Krešimir Ninčević ◽  
Roman Wan-Wendner
Keyword(s):  
Additive Manufacturing ◽  
Mechanical Performance ◽  
Peak Load ◽  
Fem Analysis ◽  
Material Model ◽  
Surface Strain ◽  
Image Correlation ◽  
Nonlinear Material ◽  
Full Field ◽  
Structural Applications

The aim of this paper is to introduce and characterize, both experimentally and numerically, three classes of non-traditional 3D infill patterns at three scales as an alternative to classical 2D infill patterns in the context of additive manufacturing and structural applications. The investigated 3D infill patterns are biologically inspired and include Gyroid, Schwarz D and Schwarz P. Their selection was based on their beneficial mechanical properties, such as double curvature. They are not only known from nature but also emerge from numerical topology optimization. A classical 2D hexagonal pattern has been used as a reference. The mechanical performance of 14 cylindrical specimens in compression is quantitatively related to stiffness, peak load and weight. Digital image correlation provides accurate full-field deformation measurements and insights into periodic features of the surface strain field. The associated variability, which is inherent to the production and testing process, has been evaluated for 3 identical Gyroid specimens. The nonlinear material model for the preliminary FEM analysis is based on tensile test specimens with 3 different slicing strategies. The 3D infill patterns are generally useful when the extrusion orientation cannot be aligned with the build orientation and the principal stress field, i.e., in case of generative design, such as the presented branching structure, or any complex shape and boundary condition.

Study on Capacity Distribution of Optimal Configuration Ratio of Urban Replenishment Station of Electric Vehicles

2020 ◽  
Vol 13 (1) ◽  
pp. 119-125
Author(s):  
Bo Zhang ◽  
Bicheng Huang ◽  
Zhongxian Wang
Keyword(s):  
Influencing Factors ◽  
Distribution Network ◽  
Peak Load ◽  
Optimal Solution ◽  
Simulation Method ◽  
Optimal Configuration ◽  
Power Station ◽  
Charging Station ◽  
Actual Configuration ◽  
The Impact

Background: This paper deeply studies the influence of the capacity distribution of urban charging and replacing power stations on the distribution network and gives the optimal solution. Objective: The optimal configuration scheme of the charging and replacing station has been given to reduce the impact of the charging and replacing station on the distribution network. Methods: First, the Monte Carlo simulation method is used to extract the influencing factors. The probability load models of the battery replacement station, the slow charging station and the fast charging station are established respectively. The capacity distribution is represented by three different types of charging and switching station configuration ratios. Furthermore, the impact of the charging and replacing power station on the economics and safety of the distribution network is analyzed. Different from other literature, the “peak-filling” model with “minimum peak load”, “maximum valley load” and “minimum peak-to-valley difference” is established, and then PSO is adopted. Results: Finally, the actual configuration is used to compare and analyze the four configuration schemes to prove the superiority of the optimization scheme. Conclusion: Three models have different key influencing factors, so that the electric vehicle load forecasting is more targeted and accurate. The results show that more battery replacement stations can reduce the impact of EV charging on the distribution network, and the construction of the supply replenishment should be based on the construction of the power station.

Investigation on V-Bending and Springback of Laminated Steel Sheets

2015 ◽  
Vol 137 (4) ◽  
Author(s):  
Qiongyao Peng ◽  
Xiongqi Peng ◽  
Yinjun Wang ◽  
Tao Wang
Keyword(s):  
Adhesive Layer ◽  
Material Model ◽  
Tensile Tests ◽  
Polymer Layer ◽  
Structural Function ◽  
Steel Sheets ◽  
Lap Shear ◽  
Industry Practice ◽  
Hyperelastic Model ◽  
Processing Optimization

Laminated steel sheet (LSS) is a novel functional material consisting of two steel sheets sandwiched by an adhesive layer. It has good vibration damping and noise absorption attributed by the middle polymer layer, and structural function owed to the two face steel sheets. Springback is an omnipresent negative phenomenon in metal sheet bending. Experiments and simulations were conducted to analyze the effects of processing and material parameters on springback of a specified LSS for the purpose of process optimization. Various tests including lap-shear, normal tensile, and viscosity analysis were carried out to obtain the mechanical behavior of the polymer layer. A neo-Hookean hyperelastic model was accordingly developed. Tensile tests of the two skin sheets were also implemented for material model. Ninety degree V-bending experiments were fulfilled as a validation on the feasibility and efficiency of finite element method and material models. A following parametric study on 88 deg V-bending of the LSS was then implemented to provide a processing optimization for industry practice.

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