Temperature Dependency of the Deformation Behavior of Hybrid CFRP/Elastomer/Metal Laminates under 3-Point Bending Loads

2019 ◽  
Vol 809 ◽  
pp. 259-265
Author(s):  
Vincent Sessner ◽  
Kay André Weidenmann
Keyword(s):  
Deformation Behavior ◽  
Galvanic Corrosion ◽  
Image Correlation ◽  
Constrained Layer Damping ◽  
Bending Vibrations ◽  
Complex Deformation ◽  
Damping Behavior ◽  
Different Temperatures ◽  
Bending Loads ◽  
Soft Elastomer

Fibre-metal-elastomer laminates offer the possibility of using material combinations which often have to deal with premature delamination, for example due to different coefficients of thermal expansion or galvanic corrosion due to different electronegativities. The present study deals with laminates made of layers of CFRP and aluminum, each of which is bonded together by an elastomer layer. The shear-soft elastomer also allows the much stiffer aluminum and CFRP layers to be sheared off against each other under bending stress. This leads to complex deformation behavior. The shear of the elastomer also plays a crucial role in the damping behavior of the laminate. Due to large shear deformations in the elastomer layer, the combination of rigid layers and soft elastomer layers shows very good damping behavior according to the principle of constrained layer damping. Since bending vibrations that occur during normal use usually have only small amplitudes, the deformation behavior is of particular interest in the elastic range. Since this deformation behavior is strongly dependent on the shear modulus of the elastomer used and this in turn is strongly influenced by temperature, the deformation behavior is characterized at different temperatures. Within the scope of this investigation, quasi-static 3-point bending tests are carried out on different laminate lay-ups in the temperature range from -40 °C to +80 °C. The laminates are consolidated by compression molding and contain two different EPDM elastomers in varying layer thicknesses, unidirectional CFRP prepreg in biaxial layer lay-up and aluminum 2024 sheets. The deformation behavior is analyzed by digital image correlation. This is used to measure both the bending line of the overall composite and strains over the layer thickness. In particular, the shear in the elastomer layers is evaluated and set in relation to the bending lines. Finally, the ability of the laminate lay-up to damp bending vibrations is evaluated.

Heat Treatment Influence on the Corrosion Resistance of a Cu-Al-Fe-Mn Bronze

2018 ◽  
Vol 69 (5) ◽  
pp. 1055-1059 ◽  
Author(s):  
Mariana Ciurdas ◽  
Ioana Arina Gherghescu ◽  
Sorin Ciuca ◽  
Alina Daniela Necsulescu ◽  
Cosmin Cotrut ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Structural Changes ◽  
Heating Temperature ◽  
Galvanic Corrosion ◽  
Cooling Water ◽  
Open Circuit ◽  
Water Quenching ◽  
Heat Treated ◽  
Different Temperatures

Aluminium bronzes are exhibiting good corrosion resistance in saline environments combined with high mechanical properties. Their corrosion resistance is obviously confered by the alloy chemical composition, but it can also be improved by heat treatment structural changes. In the present paper, five Cu-Al-Fe-Mn bronze samples were subjected to annealing heat treatments with furnace cooling, water quenching and water quenching followed by tempering at three different temperatures: 200, 400 and 550�C. The heating temperature on annealing and quenching was 900�C. The structure of the heat treated samples was studied by optical and scanning electron microscopy. Subsequently, the five samples were submitted to corrosion tests. The best resistance to galvanic corrosion was showed by the quenched sample, but it can be said that all samples are characterized by close values of open-circuit potentials and corrosion potentials. Concerning the susceptibility to other types of corrosion (selective leaching, pitting, crevice corrosion), the best corrosion resistant structure consists of a solid solution, g2 and k compounds, corresponding to the quenched and 550�C tempered sample.

scholarly journals Determination of Load-Carrying Capacity of C-Profile Glued Ti-Al Column under Temperature Environment

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3013
Author(s):  
Leszek Czechowski
Keyword(s):  
Carrying Capacity ◽  
Tensile Tests ◽  
Discrete Models ◽  
Image Correlation ◽  
Load Carrying Capacity ◽  
Lagrange Equations ◽  
Load Carrying ◽  
Different Temperatures ◽  
Influence Of Temperature On

The paper deals with an examination of the behaviour of glued Ti-Al column under compression at elevated temperature. The tests of compressed columns with initial load were performed at different temperatures to obtain their characteristics and the load-carrying capacity. The deformations of columns during tests were registered by employing non-contact Digital Image Correlation Aramis® System. The numerical computations based on finite element method by using two different discrete models were carried out to validate the empirical results. To solve the problems, true stress-logarithmic strain curves of one-directional tensile tests dependent on temperature both for considered metals and glue were implemented to software. Numerical estimations based on Green–Lagrange equations for large deflections and strains were conducted. The paper reveals the influence of temperature on the behaviour of compressed C-profile Ti-Al columns. It was verified how the load-carrying capacity of glued bi-metal column decreases with an increase in the temperature increment. The achieved maximum loads at temperature 200 °C dropped by 2.5 times related to maximum loads at ambient temperature.

Deformation Behavior of Fiber-Reinforced Hydrogel Structures

2019 ◽  
Vol 19 (03) ◽  
pp. 1950032 ◽  
Author(s):  
Yu Zhou ◽  
Jianying Hu ◽  
Zishun Liu
Keyword(s):  
Free Energy ◽  
Deformation Behavior ◽  
Free Energy Function ◽  
Fiber Reinforced ◽  
Energy Component ◽  
Complex Deformation ◽  
Finite Element Software ◽  
Buckling Behavior ◽  
Proposed Model ◽  
Anisotropic Deformation

Proposed herein is a new theory for the anisotropic deformation of fiber-reinforced hydrogels. This new model takes into account the real fabrication of the fiber-reinforced hydrogels, in which the hydrogels are polymerized with fibers and polymer solutions. The new free energy function is established by adding the anisotropic free energy component contributed by fibers into the Flory–Rehner model. The proposed model is implemented through a user-defined material subroutine (UMAT) in the finite element software package ABAQUS. In particular, the consistent tangent modulus is derived in detail. Then, several illustrative examples with analytical and numerical results are demonstrated. In order to study deformation behavior of natural materials, we design some simple bilayer structures to mimic the opening of seedpods and the closure of flowers, in which the buckling behavior of fiber-reinforced hydrogels have been demonstrated. We hope that the proposed approach may help to study more complex deformation phenomena in hydrogel structures.

Curvature Change Analysis of SMART Fibers Used for Temperature Adaptive Insulation

2019 ◽  
Author(s):  
Cameron Ripa ◽  
Andrew Latulippe ◽  
Hongwei Sun ◽  
Stephen Fossey ◽  
Christopher Drew
Keyword(s):  
Temperature Change ◽  
Coefficient Of Thermal Expansion ◽  
Bath Temperature ◽  
Image Correlation ◽  
Radius Of Curvature ◽  
Change Analysis ◽  
Thickness Change ◽  
Different Temperatures ◽  
Dependence Relationship ◽  
Relationship Of

Abstract A new method of characterizing the curvature change in thermally adaptive fibers is introduced in this paper. Based on the same principle as bi-metallic strips commonly found in thermostats, multi-component polymer fibers can be created to change their geometrical form in response to a temperature change. This works by creating fibers from two or more materials that have a mismatched Coefficient of Thermal Expansion (CTE). A temperature change leads to a change in curvature of these fibers. When fibers interact in an insulation batting structure, a temperature change leads to a thickness change in the insulation. While these fibers have visually been observed to function, there was no method to quantitatively characterize their curvature performance. This paper introduces a method that can be used to quantify fiber performance by tracking change in curvature over a specific temperature range. This is accomplished by suspending fibers on the surface of a liquid bath and changing the bath temperature. Digital images of the fiber are taken at different temperatures and analyzed using software to determine the radius of curvature. Absolute change in curvature was found to be as high as 0.5% per degree °C from 20 to −20°C for certain samples. A trend was also noted between higher initial curvature and lower overall performance. Digital image correlation was further used to investigate the time-dependence relationship of fiber curvature. Future experiments can be performed with this setup to characterize and compare curvature change performance of different fibers accurately.

Modeling of Flow Curve at High Temperature for a Ti-6Al-4V Alloy

2013 ◽  
Vol 849 ◽  
pp. 195-199
Author(s):  
Jiranuwat Porntadawit ◽  
Vitoon Uthaisangsuk ◽  
Paiboon Choungthong
Keyword(s):  
Process Design ◽  
Deformation Behavior ◽  
Constitutive Models ◽  
Strain Rates ◽  
Compression Tests ◽  
Forming Process ◽  
Flow Curves ◽  
Different Temperatures ◽  
Machine Parts ◽  
Strain Responses

Titanium alloy grade Ti-6Al-4V has been widely applied for many applications such as aircraft structural components, machine parts, and parts for medical equipments. To understand deformation behavior and microstructure evolution of the material during hot forming process is significant for achieving desired dimension and final mechanical properties of a product. In this study, stress-strain responses of the Ti-6Al-4V alloy were investigated using hot compression tests at different temperatures and strain rates. The determined flow curves of the alloy were subsequently calculated according to the constitutive models based on Cingara equation and Shafiei and Ebrahimi equation and compared with the experimental results. By this manner, influences of work hardening and dynamic recrystallization on the hot deformation behavior of material could be described. Accurate prediction of flow curves can considerably improve the forming process design.

scholarly journals Unique cyclic deformation behavior of a heavily alloyed Al–Si piston alloy at different temperatures

2012 ◽  
Vol 22 (5) ◽  
pp. 445-451 ◽  
Author(s):  
Guohua Zhang ◽  
Bingchao Li ◽  
Jianxin Zhang ◽  
Zengjian Feng ◽  
Zuoshan Wei ◽  
...  
Keyword(s):  
Cyclic Deformation ◽  
Deformation Behavior ◽  
Piston Alloy ◽  
Different Temperatures
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