scholarly journals Effect of the Stress State on the Adhesive Strength of an Epoxy-Bonded Assembly

2021 ◽  
Vol 16 (59) ◽  
pp. 311-325
Author(s):  
Sergey Smirnov ◽  
Dmitry Konovalov ◽  
Irina Veretennikova ◽  
Aleksander Pestov ◽  
Viktoria Osipova

The paper studies the adhesive strength of aluminum alloy specimens bonded with the use of an epoxy adhesive, under the tensile-shear stress state, depending on the testing temperature. Tension of modified Arcan specimens with load angles of 0, 22.5, 45, 67.5, and 90° with respect to the plane of adhesion is chosen as the experimental method. Experiments were performed at temperatures of −50, +23, and +50 °С. The analysis of the obtained results yields a linear fracture criterion and a fracture locus for the adhesive failure strain energy density, which takes into account the ratio of the elastic properties of the adhesive to those of the substrate. The region bounded by the fracture loci of adhesive strength and ultimate strain energy density determines the conditions for the safe loading of the bonded assembly in terms of the energy and force criteria of adhesive failure. The proposed fracture loci can be used, preferably simultaneously, to estimate the in-service strength and reliability of adhesively bonded assemblies.

2015 ◽  
Vol 07 (06) ◽  
pp. 1550089 ◽  
Author(s):  
Junping Shi ◽  
Xiaoshan Cao ◽  
Chao Shen

In this study, total strain theory and isotropic hardening model based on Mises yield condition are used to derive the expression for plastic strain energy density under complicated stress state. The normal and shear stress distributions of a solid cylindrical bar under a combination of tensile and torsional stresses as well as the equation and integral formula for plastic strain energy density are presented. The plastic strain energy density of critical point and the plastic strain energy intensity on the fracture plane of different materials under several typical stress states are obtained by measuring the fracture data of different materials. With the plastic strain energy intensity as the failure parameter, uniaxial tensile experiments were conducted to measure the final plastic strain energy intensity of the failure section. The plastic strain energy intensity failure criteria of the material under complex stress state are established. Combined tension–torsion tests were conducted on two types of materials, LC9 and LY12, to verify the validity and applicability of the criteria.


2020 ◽  
Vol 28 ◽  
pp. 734-742
Author(s):  
Pietro Foti ◽  
Seyed Mohammad Javad Razavi ◽  
Liviu Marsavina ◽  
Filippo Berto

2021 ◽  
Vol 230 ◽  
pp. 111716
Author(s):  
Pietro Foti ◽  
Seyed Mohammad Javad Razavi ◽  
Majid Reza Ayatollahi ◽  
Liviu Marsavina ◽  
Filippo Berto

Author(s):  
Mircea Bîrsan

AbstractIn this paper, we present a general method to derive the explicit constitutive relations for isotropic elastic 6-parameter shells made from a Cosserat material. The dimensional reduction procedure extends the methods of the classical shell theory to the case of Cosserat shells. Starting from the three-dimensional Cosserat parent model, we perform the integration over the thickness and obtain a consistent shell model of order $$ O(h^5) $$ O ( h 5 ) with respect to the shell thickness h. We derive the explicit form of the strain energy density for 6-parameter (Cosserat) shells, in which the constitutive coefficients are expressed in terms of the three-dimensional elasticity constants and depend on the initial curvature of the shell. The obtained form of the shell strain energy density is compared with other previous variants from the literature, and the advantages of our constitutive model are discussed.


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