scholarly journals Study on the mechanical response of anticlastic cold bending insulating glass and its coupling effect with uniform load

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0250463
Author(s):  
Xide Zhang ◽  
Jinzhi Liang ◽  
Dong Huang
Keyword(s):  
Mechanical Properties ◽  
Mechanical Response ◽  
Coupling Effect ◽  
Stress Transfer ◽  
Bending Test ◽  
Uniform Load ◽  
Element Analysis ◽  
Glass Thickness ◽  
Cold Bending ◽  
Cavity Thickness

Cold bending is a characteristic of significance for the beautiful curved glass curtain walls, because it affects them in terms of energy-efficiency and cost-efficiency. The increasing engineering projects call for more special studies on the mechanical properties of cold-bent glass panels, especially when the walls are built by insulating glass that is currently widely used while its relevant research is very scarce. This paper is devoted to studying the mechanical properties of anticlastic cold-bent insulating glass while taking different factors into consideration, including glass thickness, cold-bent torsion rate and cavity thickness. 9 pieces of insulating glass were manufactured for anticlastic cold-bending test and their coupled effect with identical load is also studied, and numerical finite element analysis sessions were carried out to simulate the experimental results for each one of them. Further, we analyzed the stress distribution performance of the sample pieces under cold bending and a uniform load, followed by discussions about stress transfer controls in glass plates. The results showed that the cold-bent control stress is on the surface with direct loads from cold bending and close to the cold-bent corner on the short edge, and it is transferred from the parts around the corner to the center when the uniform load plays a leading role in generating stress. This transfer could occur under a relatively small load with a small cold-bent torsion rate. A higher cold-bent torsion rate in cold bending contributed mostly to greater center stress in the glass, and as the glass thickness grows, stress and deflection at the plate center would significantly drop. However, the effect of cavity thickness on the anticlastic mechanical response of insulating glass was found to be trivial.

scholarly journals Experimental and Numerical Investigation of the Effect of Different Temperature and Deformation Speeds on Mechanical Properties and Springback behaviour in Al-Zn-Mg-Cu Alloy

Mechanika ◽  
2019 ◽  
Vol 25 (5) ◽  
pp. 406-412
Author(s):  
Suleyman Kilic
Keyword(s):  
Mechanical Properties ◽  
Rate Sensitivity ◽  
High Strength ◽  
Bending Test ◽  
Element Analysis ◽  
Cu Alloy ◽  
Modeling Process ◽  
The Finite Element Analysis ◽  
Bending Process ◽  
Loss Of Strength

Thanks to their low density and high strength, the 7XXX series aluminum alloys are widely used as a support/beam parts in the aerospace industry. This alloy is target in the lightening studies of the automotive industry and surveys for sheet metal are still in progress. It is a series of alloys that can be applied to the aging process and has the most effect on mechanical properties. As formability is quite weak, methods are investigated. In this study, tensile test, bending test and Erichsen tests are performed at different deformation rates and temperatures. As a result of the experiments, it has been seen that the formability increases at high temperature and low deformation rates. If paint baking time is long, there will be no loss of strength. Also, the bending process is modeled with the help of the finite element analysis programs and the springback estimations are examined. It is seen that the results of the modeling process are quite successful. The effect of the strain rate sensitivity is determined.

Mechanical Properties of Curved Nickel-Titanium Orthodontic Archwires Prepared by Cold Bending and Heat Bending Techniques

2017 ◽  
Vol 266 ◽  
pp. 245-251 ◽  
Author(s):  
Kanuengnit Pongpat ◽  
Surachai Dechkunakorn ◽  
Niwat Anuwongnukroh ◽  
Anak Khantachawana
Keyword(s):  
Mechanical Properties ◽  
Surface Hardness ◽  
Nickel Titanium ◽  
Open Bite ◽  
Bending Test ◽  
Niti Wire ◽  
Cold Forming ◽  
Deep Bite ◽  
Cold Bending ◽  
Orthodontic Archwires

Curved nickel-titanium (NiTi) orthodontic archwires are widely used in deep bite and open bite correction because of their extraordinary properties of shape memory and superelasticity. The aim of this study were to investigate the mechanical properties of curved NiTi archwires prepared by two different techniques; cold bending and direct electric resistance heat treatment (DERHT) bending and compare those properties to preformed curve NiTi archwires. Preformed curve archwires, 0.016x0.022 inch, were served as a control (group1). Plain archwires were curved into similar geometry as control by fingers (group2) and under the application of DERHT (group3). The three-point bending test was performed to analyze unloading force, springback and stiffness of archwires. Surface hardness was measured by Vickers micro-hardness test. The result showed that the unload force of all sample groups were similar. However, the stiffness and spring back properties of group2 and group3 were significantly higher than those of group 1(p<0.05). Moreover, surface hardness of cold forming technique and preform-curved NiTi archwire was slightly lower than those obtained from DERHT bending technique. Based on these results, the cold bending technique could provide the curved archwire with similar mechanical properties to the preform-curved NiTi archwire. Therefore, the cold bending technique was acceptable to be used as a chair-side orthodontic NiTi wire bending.

The Experiment and Finite Element Analysis of Carbon Fiber Sandwich Beam With Pyramidal Truss Core Structure

2016 ◽  
Author(s):  
Jiguang Gu ◽  
Nana Yang ◽  
Zhanyi Guo ◽  
Xiongliang Yao
Keyword(s):  
Mechanical Properties ◽  
Carbon Fiber ◽  
Permanent Deformation ◽  
Sandwich Beam ◽  
Pressure Head ◽  
Bending Test ◽  
Face Sheet ◽  
Element Analysis ◽  
Truss Core ◽  
Pyramidal Truss

A new technology method is adapted to manufacture carbon fiber lattice sandwich beam with pyramidal truss core. The flat crush test experiment is to test the resistance to compression of the carbon fiber sandwich plate with pyramidal truss core. The result shows that after the pressure head contact the specimens adequately, and the stiffness of structure is the maximum. If the load is continuing increase, the pyramidal truss core may be destroyed, and both sides of the carbon fiber panel begin tottering. It emerges permanent deformation on the structures after an uninstall. The three-point bending test of lattice sandwich beam referred to ASTM C393-00 is designed to research the mechanical properties of face sheet and pyramidal truss core of lattice sandwich beam with theoretical analysis. Load-deflection curves of the middle of lattice sandwich beam in long span and in short span tests are retained, which are applied to obtain flexure stiffness of face sheet and shear strength of pyramidal truss core. It is found that span length has some influence on damage modes of lattice sandwich beam with pyramidal truss core. Debonding between face sheet and lattice core occurs when span is larger and core collapse appears when span is smaller. Crack expansion and fracture of resin base also both emerge in these two damage modes and the crack expansion consists of two different types which are crack expansion inside the resin base and crack expansion from the indenter to the support. Contrast with other lattice sandwich beam with similar or different shapes of core in the other references, the mechanical properties of this lattice sandwich beam by this new fabrication have obvious advantage at the same relative density.

scholarly journals BENDING PROPERTIES OF A FUNCTIONALLY GRADED POLYMERIC COMPOSITE REINFORCED WITH A HYBRID NANOMATERIAL

2021 ◽  
Vol 21 (4) ◽  
pp. 302-319
Author(s):  
Mahdi M. S. Shareef ◽  
Ahmed Naif Al-Khazraji ◽  
Samir Ali Amin
Keyword(s):  
Mechanical Properties ◽  
Volume Fraction ◽  
Functionally Graded ◽  
Hybrid Nanocomposites ◽  
Bending Test ◽  
Fe Model ◽  
Al2o3 Nanoparticles ◽  
Isotropic Layer ◽  
Element Analysis ◽  
Three Point Bending

In this paper, functionally graded polymer hybrid nanocomposites have been produced by silica (SiO2) nanoparticles and alumina (Al2O3) nanoparticles distributed in a matrix of epoxy during the ultra-sonication via hand lay-up method. The variation in nanoparticles volume fraction (Vf.) has been given in the thickness direction for reaching the gradation. Each layer has a thickness of 1.2 mm through various concentrations of nanoparticles and is sequentially cast in acrylic moulds to fabricate the graded composite sheet with a 6 mm thickness. To fabricate the functionally graded layers, various concentrations of different nanoparticles (1.5% SiO2, 1% SiO2, epoxy, 2% Al2O3 and 3% Al2O3) have been used for tensile and compressive testing each isotropic layer of functionally graded material (FGM). The mechanical property that was studied for pure epoxy, isotropic and FGM was the flexural resistance. The flexural properties of FGM, isotropic nanocomposite (1% SiO2 + 2% Al2O3) and pristine epoxy, for evaluating their mechanical properties, including flexural stress-strain criteria and flexural Young's modulus, were determined via a Three-point bending test, with loading from the side of silica and alumina for the hybrid-FGM and at one side for the isotropic hybrid nanocomposite and pristine epoxy. The mechanical properties (tensile and compression) and the density of every layer were obtained for the epoxy resin and nanocomposites. They can benefit from the Finite Element Analysis (FEA) of the Three-point bending test via the Design Modeler (ANSYS workbench). The results of experiments were confirmed via building a detailed 3D FE model. Also, the advanced deformation results from the FE model were found in good agreement with the experimental outcomes.

Factors Affecting Spherical Nano-Indentation of Thin Film/Substrate Systems

2014 ◽  
Author(s):  
A. Hossain ◽  
A. Mian
Keyword(s):  
Thin Film ◽  
Mechanical Properties ◽  
Mechanical Response ◽  
Indentation Test ◽  
Element Analysis ◽  
Factors Affecting ◽  
Nano Indentation ◽  
Fea Modeling ◽  
Soft Biological Materials ◽  
Film Substrate

Great interests have been made over the last few years in the development of techniques to measure the mechanical properties of many engineering materials at the nano scale. In nano-indentation, a hard tip with known mechanical properties is pressed into a sample whose properties are unknown. The load, indentation depth and deformed area resulting from this test are then used to determine the desired mechanical properties, such as hardness and modulus. In this study, the computer-based finite element analysis (FEA) method is used to investigate factors effecting nano-indentation to ensure reliable measurement of thin film properties. First, the FEA method is used to predict the mechanical response of bulk aluminum (Al) using a spherical indenter. The numerical prediction is then compared with existing published results to validate the FEA modeling scheme. Once the model is validated, additional numerical analyses are conducted to investigate the response of Al-film deposited on different substrate materials. New mathematical formulations are proposed to determine the film modulus from nano-indentation test. The film modulus obtained from the new and existing mathematical formulations are also compared. Results obtained from this research can be used to characterize the mechanical properties of soft biological materials such as biofilm or tissue scaffolds.

scholarly journals Visco- and poroelastic contributions of the zona pellucida to the mechanical response of oocytes

2021 ◽  
Vol 20 (2) ◽  
pp. 751-765
Author(s):  
Alberto Stracuzzi ◽  
Johannes Dittmann ◽  
Markus Böl ◽  
Alexander E. Ehret
Keyword(s):  
Mechanical Properties ◽  
Zona Pellucida ◽  
Fluid Transport ◽  
Mechanical Response ◽  
Viscoelastic Model ◽  
Structural Response ◽  
Progressive Relaxation ◽  
In Vitro Fertilisation ◽  
Element Analysis

AbstractProbing mechanical properties of cells has been identified as a means to infer information on their current state, e.g. with respect to diseases or differentiation. Oocytes have gained particular interest, since mechanical parameters are considered potential indicators of the success of in vitro fertilisation procedures. Established tests provide the structural response of the oocyte resulting from the material properties of the cell’s components and their disposition. Based on dedicated experiments and numerical simulations, we here provide novel insights on the origin of this response. In particular, polarised light microscopy is used to characterise the anisotropy of the zona pellucida, the outermost layer of the oocyte composed of glycoproteins. This information is combined with data on volumetric changes and the force measured in relaxation/cyclic, compression/indentation experiments to calibrate a multi-phasic hyper-viscoelastic model through inverse finite element analysis. These simulations capture the oocyte’s overall force response, the distinct volume changes observed in the zona pellucida, and the structural alterations interpreted as a realignment of the glycoproteins with applied load. The analysis reveals the presence of two distinct timescales, roughly separated by three orders of magnitude, and associated with a rapid outflow of fluid across the external boundaries and a long-term, progressive relaxation of the glycoproteins, respectively. The new results allow breaking the overall response down into the contributions from fluid transport and the mechanical properties of the zona pellucida and ooplasm. In addition to the gain in fundamental knowledge, the outcome of this study may therefore serve an improved interpretation of the data obtained with current methods for mechanical oocyte characterisation.

scholarly journals A comparison between rotating squares and anti-tetrachiral systems: Influence of ligaments on the multi-axial mechanical response

2021 ◽  
pp. 095440622110431
Author(s):  
Luke Mizzi ◽  
Andrea Sorrentino ◽  
Andrea Spaggiari ◽  
Davide Castagnetti
Keyword(s):  
Mechanical Properties ◽  
Finite Element Analysis ◽  
Mechanical Response ◽  
The Other ◽  
Element Analysis ◽  
Strain Tolerance ◽  
Profound Influence ◽  
Mechanical Metamaterials ◽  
Auxetic Structures ◽  
High Level

Rotating unit systems are one of the most important and well-known classes of auxetic mechanical metamaterials. As their name implies, when loaded, these systems deform primarily via rotation of blocks of material, which may be connected together either directly through joints (or ‘joint-like’ connections made by overlapping vertices of the rotating units) as in the case of rotating rigid polygonal-unit systems or by ligaments/ribs as in the case of chiral honeycombs. In this work, we used Finite Element Analysis to investigate the effect which the presence/absence of ligaments has on the on-axis and off-axis mechanical properties of these systems by analysing two of the most well-known structures which characterise these two cases: the rotating square system and the anti-tetrachiral honeycomb. It was found that while the presence of ligaments has a negligible effect on the on-axis Poisson’s ratio of these systems, it has a profound influence on nearly all other mechanical properties as well as on the off-axis loading behaviour. Systems with ligaments were found to exhibit a high level of anisotropy and also a severely reduced level of stiffness in comparison to their non-ligamented counterparts. On the other hand, the rotating square system suffers from high localized stress-intensities and has a very low strain-tolerance threshold. In addition, an optimized ‘hybrid’ geometry which is specifically designed to capture the best features of both the anti-tetrachiral and rotating square system, was also analysed. This work shows the main differences between ligament-based and non-ligament-based auxetic structures and also highlights the importance of considering the off-axis mechanical response in addition to the on-axis properties when investigating such systems.

Mechanical properties of hexagonal boron nitride monolayers: Finite element and analytical predictions

2020 ◽  
Vol 234 (20) ◽  
pp. 4126-4135
Author(s):  
SK Georgantzinos ◽  
K Kariotis ◽  
GI Giannopoulos ◽  
NK Anifantis
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Boron Nitride ◽  
Mechanical Response ◽  
Hexagonal Boron Nitride ◽  
Element Analysis ◽  
Mechanics Model ◽  
Element Approach ◽  
Static Equation ◽  
Global Stiffness Matrix

The mechanical response of two-dimensional nanostructures may be significantly affected by their size. In this work, a molecular structural mechanics model is developed and is implemented in order to predict the nanomechanical behavior and calculate the corresponding elastic properties of hexagonal boron nitride sheets and describe their size-dependence. The finite element approach utilizes appropriate spring-like elements for the modeling of interactions between atoms within the hexagonal boron nitride structure, the stiffness constants of which are obtained by the molecular mechanics theory. Adopting conventional finite element techniques, the global stiffness matrix of the structure of a desired sheet size can be assembled. Applying appropriate boundary conditions, the governing equilibrium static equation can be solved and the elastic mechanical properties as Young’s modulus, shear modulus, and Poisson’s ratio of the structure can be calculated. Fitting the results of the mechanical properties calculated by the finite element analysis, analytical–empirical equations are proposed for their direct prediction for an hexagonal boron nitride sheet having the size parameters of the structure as independent variables.

Design and fabrication of aluminum honeycomb structures based on origami technology

2017 ◽  
Vol 21 (4) ◽  
pp. 1224-1242 ◽  
Author(s):  
Lijun Wang ◽  
Kazuya Saito ◽  
You Gotou ◽  
Yoji Okabe
Keyword(s):  
Mechanical Properties ◽  
Honeycomb Structure ◽  
Bending Test ◽  
Displacement Curve ◽  
Element Analysis ◽  
Folding Process ◽  
Honeycomb Structures ◽  
Aluminum Honeycomb ◽  
Deformation Behaviors ◽  
Honeycomb Cores

Aluminum alloy honeycomb structures were designed based on origami technology, and the specimens were fabricated by a new fabrication technology (i.e. a press and folding process). In folding process, a new folding device was successfully developed to achieve automatic fabrication of honeycomb structure. To prove the practicability of developed device, the honeycomb cores with claws were fabricated by this device, which were used to compare the mechanical properties with that bonded by common adhesive. The deformation behaviors and mechanical properties of honeycomb structures were investigated by the flatwise compressive test and three-point bending test. The load–displacement curve obtained at the room temperature showed that the load increased to a peak value and then tended rapidly to a constant. Besides, the deformation process approximately categorized into three zones, namely linear-elastic zone, plastic-plateau zone, and densification zone. The experimental results suggested that regardless of specimen type, the bending stiffness and compressive strengths were approximately 0.32 KN·m2and 0.39 MPa, respectively; revealing the bonded method by aluminum claws did not dramatically affect the mechanical properties of honeycomb structure. Moreover, the elastic deformation of honeycomb structure was numerically studied by the finite element analysis.

scholarly journals An Experimental Study on Cold-Bending Stress and Its Reverse-Coupling Effect with the Uniform Load on Cold-Bent SGP Laminated Glass

2021 ◽  
Vol 11 (21) ◽  
pp. 10073
Author(s):  
Xide Zhang ◽  
Chengyi Zou ◽  
Xiaoqi Yin
Keyword(s):  
Coupling Effect ◽  
Economic Benefits ◽  
Laminated Glass ◽  
Bending Stress ◽  
Ultimate Capacity ◽  
Interlayer Thickness ◽  
Uniform Load ◽  
Short Side ◽  
Cold Bending ◽  
Glass Panels

SentryGlas® Plus (SGP) laminated glass is a novel type of safety glass with high strength and stiffness. On the other hand, cold bending is a novel technique to build curved glass curtain walls, and is advantageous in terms of its greater energy efficiency and cost-effectiveness as well as its simple construction processes. The cold bending of SGP laminated glass could result in broad applications for the material and provide huge economic benefits in the field of glass curtain wall construction. To study cold-bending stress and its reverse-coupling effect with the uniform load in SGP laminated glass panels, single-corner cold-bending tests, uniform load tests, and ultimate capacity tests were conducted on eight pieces of such panels with different cold-bending curvatures and interlayer thicknesses. The results revealed that cold-bending stress in the glass panels under single-corner cold bending demonstrated a saddle-shaped distribution, with the maximum and second-largest cold-bending stresses located near the corner of the short side and the long side adjacent to the cold-bending corner, respectively. The cold-bending stress and coupling stress increased nonlinearly as the cold-bending curvature rose and the interlayer thickness became greater. Moreover, cold-bending curvature was a factor that affected the cold-bending stress and coupling stress more significantly than the interlayer thickness. The ultimate capacity and ultimate deflection of the glass panels decreased as the cold-bending curvature and interlayer thickness grew.

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