Material characterization for laminated glass composite panel

2017 ◽  
Vol 1 (81) ◽  
pp. 11-17 ◽  
Author(s):  
K. Väer ◽  
J. Anton ◽  
A. Klauson ◽  
M. Eerme ◽  
E. Õunapuu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Wave Propagation ◽  
Residual Stresses ◽  
Material Properties ◽  
Composite Panel ◽  
Laminated Glass ◽  
Glass Composite ◽  
Private Company ◽  
Viscoelastic Interlayer ◽  
Non Destructive

Purpose: Laminated glass composite panel (LGCP) with at least one flexible plastic/ viscoelastic interlayer is considered. The purpose of this paper is to determine the material properties of the constituents of LGCP required for accurate modelling of the laminated glass structures. Design/methodology/approach: The proposed approach includes the following three type of tests: non-destructive tests for determining mechanical properties of the glass layers (based on wave propagation), mechanical tests and finite element simulations for determining properties of the interlayers, measuring residual stresses in glass layers using novel methods and equipment (non-destructive, wave propagation based). Findings: Methodology and procedures for determining material properties of the LGCP. Research limitations/implications: Due to fact that the shear moduli of the viscoelastic interlayers and glass skin layers differs up to thousands times, the direct application of the classical sandwich theory may lead to inaccurate results. The layer wise plate theory with viscoelastic interlayer should be applied. In the case of layer wise theory, the material properties should be determined for each layer (not averaged properties for laminate only). Practical implications: The proposed approach allows to determine the properties of the LGCP components with high accuracy and form base for development of accurate plate model for modelling vibration, buckling and bending of the LGCP. The effect of the residual stresses is most commonly omitted in engineering applications. However, in the case of tempered glass the residual stresses are significant and have obviously impact on stress- strain behaviour of the laminated glass panel. Originality/value: Study consists of valuable parts, i.e. determining residual stresses in glass performed in cooperation with private company GlasStress Ltd. Special software and measuring equipment are developed. Further LGCP interlayer mechanical properties are tested experimentally and using simulation tools for design optimization purposes.

Application of a portable indentation rig with Rockwell indenter to determine mechanical properties and residual stresses on an aluminum plate

2020 ◽  
Vol 55 (7-8) ◽  
pp. 246-257
Author(s):  
Saba Salmani Ghanbari ◽  
Amir-Hossein Mahmoudi
Keyword(s):  
Mechanical Properties ◽  
Residual Stresses ◽  
Structural Integrity ◽  
Indentation Load ◽  
Instrumented Indentation ◽  
Unknown Parameters ◽  
Plastic Properties ◽  
Wide Range ◽  
Portable Apparatus ◽  
Non Destructive

Measuring residual stresses is still a dilemma in many engineering applications. It is even more crucial when the industrial requirements demand for a non-destructive technique in order to avoid compromising the structural integrity of the engineering components. Furthermore, estimating the mechanical properties of the materials, especially when the components are aged, is of importance. Instrumented indentation has gained much interest in recent years. There are many studies in the literature which are focused on measuring residual stresses or mechanical properties using instrumented indentation. Since in many cases there is no possibility of transferring large samples or those under service, for possible measurements, having a portable rig can be very useful. Furthermore, indentation procedure is a low-cost non-destructive method with high accuracy which is able to measure the plastic properties of material as well as its residual stresses on which the designing and construction of the portable apparatus were based. The instrumented indentation testing details were followed according to the ASTM E2546-15 standard practice. In this research, a wide range of simulations were performed on a group of aluminum alloys in order to estimate the equi-biaxial residual stresses by analyzing the indentation load–displacement curves which were obtained from the experimental outcomes. Then neural networks were employed to estimate the unknown parameters. The performance accuracy of the designed portable apparatus and the acceptable precision of the introduced method were then verified with experimental tests performed on Al 2024-T351.

Non-Destructive Measurement of Residual Stresses by an Ultrasonic Method

2013 ◽  
Author(s):  
Jacob Kleiman ◽  
Yuri Kudryavtsev ◽  
Volodimir Smilenko
Keyword(s):  
Wave Propagation ◽  
Residual Stresses ◽  
Elastic Wave ◽  
Mechanical Stress ◽  
Ultrasonic Method ◽  
Non Destructive Evaluation ◽  
Acoustic Elasticity ◽  
Destructive Measurement ◽  
Non Destructive ◽  
Applied Stresses

An ultrasonic computerized complex for measurement of residual and applied stresses UltraMARS® was recently introduced. Average through thickness stresses can be measured based on the acoustic-elasticity effect, according to which the velocity of elastic wave propagation in solids is dependent on the mechanical stress. The system was used successfully in numerous applications proving to be a reliable, fast and economical way to evaluate residual and applied stresses in materials and structures. The newly developed complex was used in a number of applications that called for non-destructive evaluation of stresses. Examples of such applications will be discussed in the paper. The system was further developed to allow for measurement of subsurface and surface stresses in structural materials and made of them structures.

scholarly journals Influence of material delivery condition on residual stresses and part properties during forward rod extrusion

2020 ◽  
Author(s):  
Andreas Jobst
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Stress Distribution ◽  
Residual Stresses ◽  
Ferritic Stainless Steel ◽  
Material Properties ◽  
Work Hardening ◽  
Efficient Production ◽  
Microhardness Distribution ◽  
Component Manufacturing

During the manufacturing of semi-finished products, the material is subjected to various forming steps to achieve the final geometry. In order to reduce the work hardening introduced and to ensure a good formability, it is annealed before component manufacturing. Forming technologies like forward rod extrusion are well-established methods for an efficient production of resilient components. In this process however, an inhomogeneous pre-strengthening of the material influences the stress distribution during forming and therefore the mechanical properties and the residual stresses in the component. Since they affect the parts operating behaviour, knowledge of the influence of the delivery condition of the material is necessary. The aim in this paper is to derive dependencies between material properties and the resulting residual stresses and work hardening in the component. Due to the increasing application, ferritic stainless steel X6Cr17 in the skin passed (+LC) and soft annealed (+A) states is used. Residual stresses, microstructure and microhardness distribution of both material states are compared regarding the rods and extruded parts. The effects of the delivery condition are evaluated by comparing process and component properties.

Cytocompatibility and Material Properties of Poly-carbonate Urethane/Carbon Nanofiber Composites for Neural Applications

2003 ◽  
Vol 774 ◽  
Author(s):  
Janice L. McKenzie ◽  
Michael C. Waid ◽  
Riyi Shi ◽  
Thomas J. Webster
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanofibers ◽  
Material Properties ◽  
Carbon Nanofiber ◽  
Scar Tissue ◽  
Tissue Response ◽  
Positive Interactions ◽  
Weight Percentage ◽  
Poly Carbonate

AbstractCarbon nanofibers possess excellent conductivity properties, which may be beneficial in the design of more effective neural prostheses, however, limited evidence on their cytocompatibility properties exists. The objective of the present in vitro study was to determine cytocompatibility and material properties of formulations containing carbon nanofibers to predict the gliotic scar tissue response. Poly-carbonate urethane was combined with carbon nanofibers in varying weight percentages to provide a supportive matrix with beneficial bulk electrical and mechanical properties. The substrates were tested for mechanical properties and conductivity. Astrocytes (glial scar tissue-forming cells) were seeded onto the substrates for adhesion. Results provided the first evidence that astrocytes preferentially adhered to the composite material that contained the lowest weight percentage of carbon nanofibers. Positive interactions with neurons, and, at the same time, limited astrocyte functions leading to decreased gliotic scar tissue formation are essential for increased neuronal implant efficacy.

Non-Destructive Testing of Thermoplastic Carbon Composite Structures

2020 ◽  
Vol 2020 (1) ◽  
pp. 34-52
Author(s):  
Rafał Szymański
Keyword(s):  
Composite Structures ◽  
Ultrasonic Method ◽  
Composite Panel ◽  
Aviation Industry ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Pulse Technique ◽  
Thermoplastic Matrix ◽  
The Subject ◽  
Non Destructive

AbstractThe article is in line with the contemporary interests of companies from the aviation industry. It describes thermoplastic material and inspection techniques used in leading aviation companies. The subject matter of non-destructive testing currently used in aircraft inspections of composite structures is approximated and each of the methods used is briefly described. The characteristics of carbon preimpregnates in thermoplastic matrix are also presented, as well as types of thermoplastic materials and examples of their application in surface ship construction. The advantages, disadvantages and limitations for these materials are listed. The focus was put on the explanation of the ultrasonic method, which is the most commonly used method during the inspection of composite structures at the production and exploitation stage. Describing the ultrasonic method, the focus was put on echo pulse technique and the use of modern Phased Array heads. Incompatibilities most frequently occurring and detected in composite materials with thermosetting and thermoplastic matrix were listed and described. A thermoplastic flat composite panel made of carbon pre-impregnate in a high-temperature matrix (over 300°C), which was the subject of the study, was described. The results of non-destructive testing (ultrasonic method) of thermoplastic panel were presented and conclusions were drawn.

Effect of the Weld Joint Configuration on Stressed Components, Residual Stresses and Mechanical Properties

2014 ◽  
Vol 56 (4) ◽  
pp. 279-284 ◽  
Author(s):  
Bekir Çevik ◽  
Alpay Özer ◽  
Yusuf Özçatalbaş
Keyword(s):  
Mechanical Properties ◽  
Residual Stresses ◽  
Weld Joint ◽  
Joint Configuration

Influence of the applied pressure of the transducer on the propagation speed of the ultrasonic wave in wood

Holzforschung ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Edgar V.M. Carrasco ◽  
Rejane C. Alves ◽  
Mônica A. Smits ◽  
Vinnicius D. Pizzol ◽  
Ana Lucia C. Oliveira ◽  
...  
Keyword(s):  
Wave Propagation ◽  
Applied Pressure ◽  
Pressure Gauge ◽  
Eucalyptus Grandis ◽  
Propagation Speed ◽  
Ultrasonic Waves ◽  
Ultrasonic Speed ◽  
Wave Propagation Speed ◽  
Propagation Technique ◽  
Non Destructive

Abstract The non-destructive wave propagation technique is used to estimate the wood’s modulus of elasticity. The propagation speed of ultrasonic waves is influenced by some factors, among them: the type of transducer used in the test, the form of coupling and the sensitivity of the transducers. The objective of the study was to evaluate the influence of the contact pressure of the transducers on the ultrasonic speed. Ninety-eight tests were carried out on specimens of the species Eucalyptus grandis, with dimensions of 120 × 120 × 50 mm. The calibration of the pressure exerted by the transducer was controlled by a pressure gauge using a previously calibrated load cell. The robust statistical analysis allowed to validate the experimental results and to obtain consistent conclusions. The results showed that the wave propagation speed is not influenced by the pressure exerted by the transducer.

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