Evaluation of a structural epoxy adhesive for timber-glass bonds under shear loading and different environmental conditions

2019 ◽  
Vol 95 ◽  
pp. 102425 ◽  
Author(s):  
Žiga Unuk ◽  
Andrej Ivanič ◽  
Vesna Žegarac Leskovar ◽  
Miroslav Premrov ◽  
Samo Lubej
2020 ◽  
Vol 91 (12) ◽  
pp. 7-15 ◽  
Author(s):  
Omid Sam-Daliri ◽  
Mohammadreza Farahani ◽  
Alireza Araei

Carbon nanotubes (CNT) are ideally suited to be employed for damage sensing in fiber rein- forced composite structures. In this work, the capability of CNTs for crack extension of a single lap Al-Al adhesive joints (SLJ) under shear load is studied using electrical resistance change. Different weight per- cent of CNT are added to epoxy adhesive. Epoxy adhesive with high concentration of CNT is obtained during shear loading to have the maximum strength and provide the best sensory properties. To provide a more concise evaluation of the crack extension in the adhesive layer under shear load, artificial defects are embedded into the SLJ specimens. The effects of square and circular defects with two different sizes on the crack extension in the adhesive layer are evaluated. The results showed that the maximum relative resistance change has occurred by 220% when the microcracks are initiated and accordingly developed from the nanoadhesive and changed its direction from the Square defect boundary. Additionally, in comparison with interface fracture in defective adhesive joint, when a part of crack grows through the adhesive layer, the resistance change showed higher values.


In the previous study by the author, a numerical model to predict the thermal contrasts resulting from subsurface voids (i.e. delaminations) in concrete under a given set of environmental conditions was developed using the finite element method. The model was verified using the experimental test data, and the results indicated that the model could be an effective tool to support the thermography inspection of the concrete. In this present study, the use of the verified model to evaluate the effects of materials present in the void created by the delamination expected to influence the detectability of the subsurface voids. The effect of this parameter on the thermal contrast developed on the surface above a subsurface delamination was assessed under a specific set of environmental conditions. The results indicated that air-filled void produced a significant thermal contrast compared to water-filled void, ice-filled void, and epoxy adhesive-filled void.


Author(s):  
K. Ohi ◽  
M. Mizuno ◽  
T. Kasai ◽  
Y. Ohkura ◽  
K. Mizuno ◽  
...  

In recent years, with electron microscopes coming into wider use, their installation environments do not necessarily give their performance full play. Their environmental conditions include air-conditioners, magnetic fields, and vibrations. We report a jointly developed entirely new vibration isolator which is effective against the vibrations transmitted from the floor.Conventionally, large-sized vibration isolators which need the digging of a pit have been used. These vibration isolators, however, are large present problems of installation and maintenance because of their large-size.Thus, we intended to make a vibration isolator which1) eliminates the need for changing the installation room2) eliminates the need of maintenance and3) are compact in size and easily installable.


2021 ◽  
Vol 147 (3) ◽  
pp. 04020177
Author(s):  
Daniela Dominica Porcino ◽  
Theodoros Triantafyllidis ◽  
Torsten Wichtmann ◽  
Giuseppe Tomasello

2020 ◽  
pp. 67-72
Author(s):  
A. V. Konkov ◽  
D. V. Golovin

The influence of environmental conditions on a sound pressure reproduced by the primary method in the measuring chambers of the Pistonphone in the frequency range from 1 mHz to 250 Hz is estimated. Numerical estimations of influence of environmental conditions on sound pressure in pistonphone measuring chambers are given and special requirements to system of maintenance of required external conditions are specified.


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