POSOUZENÍ MOŽNOSTI URČOVÁNÍ KOHEZNÍ PEVNOSTI ZKOUŠKOU V KRUTU

POSSIBILITY OF ADHESIVE STRENGTH EVALUATION BY TORSION TEST

conference paper

Czech

The contribution deals with an experimental identification of the cohesive strength of two materials connection by means of a torsion test. The aim of this work is to find such a way of cohesion strength measuring that is independent on dimensions of the specimen. The specimen made of a cylindrical steel bar with one end cast in epoxy resin has been developed. The first idea was to test specimen made of steel and rubber but technological and financial requirements made us to use epoxy resin instead of rubber. The variable specimen parameters are the connection length and diameter of the steel bar. By comparing the measurement results of specimens with various dimensions we were to prove the independence of the adhesive strength on dimensions of specimen but it failed, probably due to the high elastic modulus of resin. According to computational modeling the stress distribution along the connection length is not constant and the difference between extreme shear stress along the connection length increases with this length. Also the elastic modulus of resin considerably influences the difference between extreme shear stress. These reasons forced us to develop another type of specimen (type B) that has not been tested yet but the numerical modelling shows that this type could be better for our purpose.

The contribution deals with an experimental identification of the cohesive strength of two materials connection by means of a torsion test. The aim of this work is to find such a way of cohesion strength measuring that is independent on dimensions of the specimen. The specimen made of a cylindrical steel bar with one end cast in epoxy resin has been developed. The first idea was to test specimen made of steel and rubber but technological and financial requirements made us to use epoxy resin instead of rubber. The variable specimen parameters are the connection length and diameter of the steel bar. By comparing the measurement results of specimens with various dimensions we were to prove the independence of the adhesive strength on dimensions of specimen but it failed, probably due to the high elastic modulus of resin. According to computational modeling the stress distribution along the connection length is not constant and the difference between extreme shear stress along the connection length increases with this length. Also the elastic modulus of resin considerably influences the difference between extreme shear stress. These reasons forced us to develop another type of specimen (type B) that has not been tested yet but the numerical modelling shows that this type could be better for our purpose.

Torsion test, cohesive strength, finite element method

BURŠA, J.

2003

3. 6. 2002

UTAM AS CR?

Prague, CZ

80-01-02547-0

Proceedings of the 40th International Conference Experimental Stress Analysis 2002

31

34

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