An Overview of Fatigue Testing Systems for Metals under Uniaxial and Multiaxial Random Loadings

Abstract

This paper presents an overview of fatigue testing systems in high-cycle regime for metals subjected to uniaxial and multiaxial random loadings. The different testing systems are critically discussed, highlighting advantages and possible limitations. By identifying relevant features, the testing systems are classified in terms of type of machine (servo-hydraulic or shaker tables), specimen geometry and applied constraints, number of load or acceleration inputs needed to perform the test, type of loading acting on the specimen and resulting state of stress. Specimens with plate, cylindrical and more elaborated geometry are also considered as a further classification criterion. This review also discusses the relationship between the applied input and the resulting local state of stress in the specimen. Since a general criterion to classify fatigue testing systems for random loadings seems not to exist, the present review—by emphasizing analogies and differences among various layouts—may provide the reader with a guideline to classify future equipment.

Fatigue Analysis of Long-Span Steel Truss Arched Bridge Part I: Experimental and Numerical Study of Orthotropic Steel Deck

“…Macek et al [18] proposed a mixed-mechanics measurement method to determine the three-dimensional port damage of specimens with fatigue bending loading history. Furthermore, the fatigue performance evaluation methods of a steel bridge deck mainly include the nominal stress method, hot spot stress method, and notch stress Metals 2022, 12, 1117 2 of 11 method [19][20][21][22][23]. The nominal stress method is convenient for calculation and engineering applications, which are widely adopted in bridge specifications [24][25][26][27].…”

Experimental strain‐based vibration control to obtain the fatigue strain limit by the staircase method

“…A considerable amount of literature has been published on electro‐dynamic shaker in order to achieve a steady stress/strain response. Among which, one approach is to use force as the input excitation [8,9] . Hooreweder et al [10] used an electro‐shaker which controls the force directly through stiff stinger at the free end of specimen instead of base excitation.…”

“…Among which, one approach is to use force as the input excitation. [8,9] Hooreweder et al [10] used an electro-shaker which controls the force directly through stiff stinger at the free end of specimen instead of base excitation. Yet, control of force needs a pre-stress for sensor and lose the advantage of multiaxis excitation.…”

Using the Effect of Compression Stress in Fatigue Analysis of the Roller Bearing for Bimodal Stress Histories

“…The onset of fatigue cracks may occur due to material imperfections, structural discontinuities, or stress concentrators [ 3 , 4 , 5 , 6 , 7 , 8 ]. The applied fatigue loads may be uniaxial (with one stress component), biaxial (with two stress components), or multiaxial (with more than two stress components) [ 9 , 10 , 11 ]. In the case of uniaxial random loadings, classical methods such as rainflow counting, cumulative damage models, and S-N curves can be used [ 10 ].…”

“…Despite the availability of many multiaxial high-cycle criteria, it is difficult to find a single universal model [ 16 ]. Another limitation of the existing criteria is that, while they can be applied for the analysis of mechanical parts in which cyclic constant amplitude stresses occur, in practical applications, random or quasi-random loads occur [ 9 ]. The application of the multiaxial high-cycle fatigue criteria for such loading conditions requires additional methods, such as the rainflow counting algorithm, to determine uniform alternating cycles for fatigue analysis [ 17 ].…”