Material characterization of structural adhesives in the lap shear mode. 1. The effects of rate

1984 ◽  
Vol 23 (3) ◽  
pp. 426-434 ◽  
Author(s):  
Erol Sancaktar ◽  
Steven C. Schenck ◽  
Shrikant Padgilwar
Keyword(s):  
Material Characterization ◽  
Shear Mode ◽  
Structural Adhesives ◽  
Lap Shear

Constitutive Behavior and Testing of Structural Adhesives

1987 ◽  
Vol 40 (10) ◽  
pp. 1393-1402 ◽  
Author(s):  
Erol Sancaktar
Keyword(s):  
Mechanical Model ◽  
Material Characterization ◽  
Constitutive Relations ◽  
Superposition Principle ◽  
Surface Preparation ◽  
Ring Test ◽  
Stress Strain ◽  
Testing Procedures ◽  
Structural Adhesives

Material characterization of structural adhesives in the bulk and bonded forms is discussed. Constitutive relations used for describing stress–strain data are reviewed. The difficulties associated with adhesive characterization in the bonded form are cited. Common testing procedures for adhesive characterization in the bulk and bonded forms are reviewed. In presenting the constitutive relations used in material characterization of structural adhesives, deformation theories introduced by Hencky are reviewed first. The modifications made in this theory to render it rate dependent and bilinear are discussed and applications to adhesive characterization are cited. Application of linear viscoelasticity, mechanical model characterization, and its use in describing the dependence of adhesive and cohesive strengths on rate, temperature, and bond thickness are presented. The time–temperature superposition principle and three-dimensional stress–strain relations in integral and differential operator forms are reviewed. Frequent assumptions for dilatation and distortion operations are presented. Procedures for describing nonlinear viscoelastic behavior are reviewed. It is pointed out that the extent of nonlinearity is dependent on both the stress level and the time scale. The use of nonlinear spring and dashpot elements, nonlinear differential operators, and perturbation of elastic and viscous coefficients are cited. Prandtl’s incremental theory of plasticity and its extension in the form of over-stress theory is presented. The incorporation of this over-stress idea into the viscoelastic mechanical model characterization is discussed. The modified Bingham model and the Chase–Goldsmith model developed in this fashion and their application to adhesive material characterization are presented. The use of empirical relations for the description of creep behavior is discussed. Prediction of shear behavior based on bulk tensile data is demonstrated. It is suggested that characterization of adhesive behavior in the bonded form should include the application of stress analysis, fracture mechanics, polymer chemistry and surface analysis techniques. In testing bonded samples the use of thick adherend symmetric single lap geometry or napkin ring test geometry is advised and it is suggested that the specimens should be prepared with the same surface preparation and cure techniques.

Synthesis and Characterization of Modified Phenylethynyl Imides

1998 ◽  
Vol 10 (2) ◽  
pp. 175-180 ◽  
Author(s):  
B J Jensen ◽  
A C Chang
Keyword(s):  
Molecular Weight ◽  
Ambient Temperature ◽  
High Performance ◽  
Synthesis And Characterization ◽  
Tensile Shear ◽  
Structural Adhesives ◽  
Aerospace Applications ◽  
Lap Shear ◽  
Ongoing Effort

As an ongoing effort to develop structural adhesives for high-performance aerospace applications, recent work has focused on phenylethynyl terminated imide (PETI) oligomers. The work reported herein involves the synthesis and characterization of a series of phenylethynyl containing oligomers designated LARC™ MPEI (modified phenylethynyl imide). These oligomers presumably contain mixtures of linear, branched and star-shaped molecules. The fully imidized polymers exhibited minimum melt viscosities as low as 600 poise at 335 °C, significantly lower than equivalent molecular weight linear materials. Ti/Ti lap shear specimens processed at 288 °C under 15 psi showed tensile shear strengths as high as ∼6000 psi and ∼5200 psi at ambient temperature and 177 °C respectively. The chemistry and properties of these new MPEIs are presented and compared with an optimized linear PETI, LARC™ PETI-5.

Characterization of FRP-to-concrete bonded interface Description of the single lap shear test

2009 ◽  
Vol 13 (9) ◽  
pp. 1073-1082
Author(s):  
Sylvain Chataigner ◽  
Jean-François Caron ◽  
Karim Benzarti ◽  
Marc Quiertant ◽  
Christophe Aubagnac
Keyword(s):  
Shear Test ◽  
Lap Shear ◽  
Bonded Interface ◽  
Lap Shear Test ◽  
Single Lap Shear Test

scholarly journals Correlation of Global Quantities at Material Characterization of Pressure-Sensitive Materials Using Sharp Indentation Testing

Lubricants ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 29
Author(s):  
Carl F. O. Dahlberg ◽  
Jonas Faleskog ◽  
Per-Lennart Larsson
Keyword(s):  
Finite Element ◽  
Material Characterization ◽  
Pressure Sensitivity ◽  
Pressure Sensitive ◽  
The Mean ◽  
Sharp Indentation ◽  
Von Mises ◽  
Von Mises Plasticity ◽  
Hardness Values

Correlation of sharp indentation problems is examined theoretically and numerically. The analysis focuses on elastic-plastic pressure-sensitive materials and especially the case when the local plastic zone is so large that elastic effects on the mean contact pressure will be small or negligible as is the case for engineering metals and alloys. The results from the theoretical analysis indicate that the effect from pressure-sensitivity and plastic strain-hardening are separable at correlation of hardness values. This is confirmed using finite element methods and closed-form formulas are presented representing a pressure-sensitive counterpart to the Tabor formula at von Mises plasticity. The situation for the relative contact area is more complicated as also discussed.

Piezoelectric Shear Mode Inkjet Actuator

2001 ◽  
Vol 687 ◽  
Author(s):  
Jürgen Brünahl ◽  
Alex M. Grishin ◽  
Sergey I. Khartsev ◽  
Carl Österberg
Keyword(s):  
Electromechanical Coupling ◽  
Microelectromechanical Systems ◽  
Electromechanical Coupling Factor ◽  
Coupling Factor ◽  
Shear Mode ◽  
Drop On Demand ◽  
Ink Jet ◽  
Ferroelectric Hysteresis ◽  
Comprehensive Characterization

AbstractWe report on comprehensive characterization of piezoelectric shear mode inkjet actuators micromachined into bulk Pb(Zr0.53Ti0.47)O3 (PZT) ceramics. The paper starts with an overview of different inkjet technologies such as continuous jet and drop-on-demand systems, whereat main attention is turned on piezoelectric systems particularly Xaar-type shear mode inkjet color printheads. They are an example of complex microelectromechanical systems (MEMS) and comprise a ferroelectric array of 128 active ink channels (75νm wide and 360νm deep). Detailed information about manufacturing and principles of operation are given. Several techniques to control manufacturing processes and to characterize properties of the piezoelectric material are described: dielectric spectroscopy to measure dielectric permittivity ε and loss tanσ; ferroelectric hysteresis P-E loop tracing to get remnant polarization Pr and coercive field Ec, and a novel pulsed technique to quantify functional properties of the PZT actuator such as acoustic resonant frequencies and electromechanical coupling factor. Stroboscope technique has been employed to find correlation between the degradation of ink-jet performance and heat/high voltage treatment resulting in ferroelectric fatigue.

Sign in / Sign up

Export Citation Format

Share Document