Stručni rad

https://doi.org/10.19279/TVZ.PD.2024-12-2-03

A CONTRIBUTION TO THE UNDERSTANDING OF FAILURE THEORIES

Branimir Markulin Grgić ; Tehničko veleučilište u Zagrebu, Vrbik 8, 10000 Zagreb, Hrvatska *
Vladimir Markulin Grgić ; Tehničko veleučilište u Zagrebu, Vrbik 8, 10000 Zagreb, Hrvatska *
Miroslav Radaković ; Tehničko veleučilište u Zagrebu, Vrbik 8, 10000 Zagreb, Hrvatska *
Ante Zaninović ; Tehničko veleučilište u Zagrebu, Vrbik 8, 10000 Zagreb, Hrvatska *

* Dopisni autor.

Sažetak

One of the basic tasks of a mechanical engineer is designing. There are three designing criteria: strength, stiffness and stability. According to the strength criterion, the stress may at no point be higher than the permissible stress for the given material and type of load. Stress is an internal force distributed per unit area of the body. Each construction is designed for a certain load. The load is represented by external forces and moments acting on it. The critical points of the construction are the places with the highest stresss, and that is where strength should be controlled.It is easy to determine whether the strength is satisfactory in the case of a uniaxial state, for example, as in tensile load or pure bending – all that is needed is to compare the calculated stress with the allowable one for that material and that type of load. The problem occurs with biaxial and triaxial stress states, caused by complex loads. The critical stress should be determined experimentally for all possible combinations σ1 : σ2 : σ3 .The meaning of strength theories is to predict the occurrence of the critical state of a structural element by comparing the actual state of stress in the observed element with the mechanical properties of the material (tensile strength or yield strength) the element is made of, which can be easily determined with the help of a tensile testing machine in the laboratory, by exposing the test specimen to axial load. Strength theories predict the failure occurrence in the case of complex static loading.

Ključne riječi

failure theory; failure; principal stresses; ductile materials; brittle materials

Hrčak ID:

329245

URI

https://hrcak.srce.hr/329245

Datum izdavanja:

20.11.2024.

Podaci na drugim jezicima: hrvatski

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