scholarly journals Fatigue behaviour of selected materials under multiaxial asynchronous loadings

2019 ◽  
Vol 300 ◽  
pp. 15006 ◽  
Author(s):  
Łukasz Pejkowski ◽  
Dariusz Skibicki ◽  
Jan Seyda
Keyword(s):  
Fatigue Life ◽  
Aluminium Alloy ◽  
Significant Influence ◽  
Fatigue Behaviour ◽  
Cyclic Stress ◽  
Strain Response ◽  
Strain Components ◽  
Thin Walled ◽  
The Difference ◽  
Multiaxial Loadings

Four types of materials: PA38 aluminium alloy, E235 steel, E355 steel and 1.4301 austenitic steel were subjected to low-cycle multiaxial loadings. All tests were strain-controlled and typical, thin-walled, hollow specimens were used. Various synchronous and asynchronous loadings were applied. The analysis of experimental results involved: cyclic stress-strain response, fatigue life and observation of microcracks behaviour on the surfaces of fatigued specimens. Obtained results indicate that the difference in the strain components frequency of the asynchronous loadings has a significant influence on the fatigue behaviour of the materials.

A New Approach to the Evaluation of Fatigue Under Multiaxial Loadings

1981 ◽  
Vol 103 (2) ◽  
pp. 118-125 ◽  
Author(s):  
Y. S. Garud
Keyword(s):  
Fatigue Life ◽  
Constitutive Relations ◽  
Cyclic Stress ◽  
Fatigue Tests ◽  
Plastic Work ◽  
Strain Response ◽  
New Approach ◽  
Hardening Rule ◽  
Multiaxial Loadings ◽  
Good Agreement

A critical review of the methods for evaluating fatigue of metals under simple (proportional) and complex (nonproportional) loadings indicates that most of the criteria are expressed in terms of either stresses or strains. In this paper a new approach to the evaluation of fatigue under these loadings is proposed. This approach is based upon the idea of relating fatigue life to the plastic work during a cycle of the loading. A procedure is outlined for the calculation of plastic work which involves explicit considerations of the material constitutive relations. It is based on the structure of modern plasticity theories and a new “hardening rule.” Validity of the constitutive relations to predict the cyclic stress-strain response is demonstrated for out-of-phase multiaxial loadings. Available experimental results of fatigue tests under out-of-phase loadings are shown to be in good agreement with the predictions using the new approach.

Measurement on Scale-Induced Fatigue Behaviour for Railway Axle

2008 ◽  
Vol 44-46 ◽  
pp. 65-70 ◽  
Author(s):  
Yong Xiang Zhao ◽  
Bing Yang ◽  
Ming Fei Feng
Keyword(s):  
Fatigue Life ◽  
Carbon Steel ◽  
Fatigue Limit ◽  
Fatigue Behavior ◽  
Fatigue Behaviour ◽  
Railway Axle ◽  
Material Fatigue ◽  
Lz50 Steel ◽  
The Difference

Transferring of fatigue behavior is investigated from material to structure for Chinese railway LZ50 axle carbon steel. S-N data in mid-fatigue life range and fatigue limit data of smooth small specimens are applied for material fatigue behavior. Real axles and similar smooth bigger specimens were tested with respect to fatigue limits. The data of real axles reveal the difference between material and a special structure. And the data of similar specimens play a role of bridge to connect material and material structures. Probabilistic transferring relations are deduced by the data from material, to similar specimens, and then to structures at the fatigue limit phase. Structural probabilistic S-N curves are obtained by the material fatigue behavior to extend the transferring relations to entire fatigue life range. Determinations of the fatigue behavior of the groove of LZ50 steel axle indicate availability of the present investigation.

Influence of Process-Related Defects on the Fatigue Behaviour of Welded Aluminium Joints at Very High Cycles

2014 ◽  
Vol 891-892 ◽  
pp. 1476-1481 ◽  
Author(s):  
Martin Cremer ◽  
Anton Kolyshkin ◽  
Martina Zimmermann ◽  
Hans Jürgen Christ
Keyword(s):  
Fatigue Life ◽  
Cross Sections ◽  
Base Material ◽  
Threshold Value ◽  
Fatigue Behaviour ◽  
Cyclic Stress ◽  
Fatigue Tests ◽  
Filler Material ◽  
Weld Defects ◽  
Very High

The influence of geometrical notch and weld defects (pores and incomplete fusions) on the fatigue behaviour at very high numbers of loading cycles is shown for welded samples made of the base material EN AW-5083 and EN AW-6082 and the filler material S Al 5183. High frequency fatigue tests with specimens highest stressed cross-sections representing different welding zones show no endurance limit up to 2·109 load cycles. The weakest link of the weld seams are the geometrical notch and (if present) pores and incomplete fusions in the seam interior and at the surface. Considering weld defects in the filler material as fatigue crack initiating notches, a threshold value for the cyclic stress intensity factor (ΔKmin) of 0.9 MPam was found. Using ΔKmin the fatigue life of the samples is discussed on the basis of stress amplitude, the projected area of the defect and its position. X-ray examinations revealed a good correlation between the failure-relevant defect areas and the overall fatigue life of welded samples.

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