On the need to decompose fatigue strain signals associated to fatigue life assessment of the AISI 1045 carbon steel
Introduction
Fatigue is a phenomenon of failing a component under cyclic loading prior to its ultimate stress. Theories of failure describe the condition for failure, such as application of linear damage accumulation of the Palmgren–Miner rule, which was based on the hypothesis on total damage [1], [2]. In any related application, a failure in specimens occurs when applied or external stresses exceed a possible value of maximum tensile stress, maximum compressive stress, or maximum shear stress. In a case of fatigue, failure will occur earlier for the maximum value of design stress. Fatigue can occur in a metallic material because of repeated application of stress and strain, especially those changes that lead to cracking or failure [3], [4].
For numerous automotive components, the primary mode of failure can be attributed to fatigue damage resulting from the application of variable amplitude loading. Predicting the life of the part stressed above the endurance limit is, at best, a rough procedure, especially for components such as automobile engine, steering, and suspension parts [2], [5]. For these cases, strain-based approach is commonly used to predict fatigue life [3], [6]. Strain-life fatigue model relates plastic deformation, which occurs at a localised region where fatigue cracks begin to the durability of the structure. This model is often used for ductile materials at relatively short fatigue lives. This approach can also be used where there is little plasticity at long fatigue lives. Therefore, this comprehensive approach can be used in place of stress-based approach [7]. Various approaches and techniques can be used to analyse fatigue data, such as root mean square (r.m.s.), and power spectral density (PSD) [8]. Those techniques and approaches were applied in previous works [9], [10] to evaluate fatigue damage, predict fatigue life, and assess fatigue behaviour.
Consequently, this research uses backward analysis, which can split fatigue data into various specified frequencies. It focusses on the investigation of a new statistical-based data scattering observation, namely Integrated Kurtosis-based Algorithm for Z-filter (I-kaz), in assessing fatigue damaging behavioural pattern of the AISI 1045 Carbon Steel using the strain decomposition approach into three different frequency ranges, i.e. Low frequency (LF), Medium frequency (MF), and High frequency (HF). Strain signals were collected via fatigue test at three different applied stresses at 305 MPa, 325 MPa, and 345 MPa. The I-kaz technique was used to decompose signals into designated frequency ranges as well as to provide a three-dimensional (3D) diagram for determining the statistical fatigue damage pattern. In addition, significant coefficients were calculated to observe fatigue life representation.
Section snippets
Fatigue life assessment for metallic materials
Fatigue damage is one type of failure mode for engineering structural components. In the previous century, several accidents were caused by fatigue cracks [11], such as aircraft and railway axles. These problems were investigated by August Wöhler. Several catastrophic failures of aircraft structures were caused by fatigue, which occurred in the 20th century [12]. Failures occur even when the maximum value of the cyclic load is much lower compared with the static strength of the material.
Materials and specimen design
AISI 1045 carbon steel is a medium carbon steel with great strength and hardness, and this kind of steel series is used extensively by all industry sectors for applications requiring more strength and wear resistance compared with typical applications of low-carbon mild steel. The numerous applications of this AISI 1045 steel in industries cannot be overemphasized. It is a medium tensile steel with the nominal tensile strength in the range of 570–850 MPa. In real applications, this steel can be
Results and discussion
Fig. 8 shows that three applied stresses at 305 MPa, 325 MPa, and 345 MPa, showing similar patterns to the constant amplitude loadings. In addition, Fig. 9 shows strain signals collected from an initial point until the end of test for all applied stresses. Fig. 9(a) shows almost a constant strain range because no obvious changes are seen in strain values from early until failure. Fig 9(b) shows that the strain values slightly increase from initial to breakage point. However, in Fig 9(c), strain
Conclusions
This paper discussed the evaluation of the I-kaz technique produced from the procedure of signal decomposition and were then compared to the fatigue damage criterion. The strain signals were decomposed into three frequency ranges. It was found that LF signal produced the highest fatigue damage compared to MF and HF signal. This LF-produced damage was compared to the damage from original strain. The highest damage values for original strain and LF strain were found to be at 2.803 × 10−5 and 2.485 ×
Acknowledgement
The authors would like to express their gratitude to Universiti Kebangsaan Malaysia and Ministry of Higher Education, Malaysia [Funding Grant No.: UKM-KK-03-FRGS0118-2010].
References (45)
- et al.
The fatigue damage development in a cast Al–Si–Cu alloy
Mater Des
(2011) - et al.
Fatigue life prediction: a continuum damage mechanics and fracture mechanics approach
Mater Des
(2012) - et al.
The reliability of test results from simple test samples in predicting the fatigue performance of automotive components
Mater Des
(2007) - et al.
Strain-controlled fatigue properties of dissimilar welded joints between Ti–6Al–4V and Ti17 alloys
Mater Des
(2013) A unified model of fatigue kinetics based on crack driving force and material resistance
Int J Fatigue
(2007)- et al.
Total fatigue life prediction for Ti-alloys airframe structure based on durability and damage-tolerant design concept
Mater Des
(2010) - et al.
Fatigue properties of transformation-induced plasticity and dual-phase steels for auto-body lightweight: experiment, modelling and application
Mater Des
(2010) - et al.
Strain-controlled fatigue properties of steels and some simple approximations
Int J Fatigue
(2000) - et al.
Cumulative fatigue damage and life prediction theories: a survey of the state of the art for homogeneous materials
Int J Fatigue
(1998) - et al.
Life assessment for metallic materials with the use of the strain criterion for low cycle fatigue
Int J Fatigue
(2009)
Strain-controlled fatigue properties of dissimilar welded joints between Ti–6Al–4V and Ti17 alloys
Mater Des
Frequency based fatigue analysis and temperature effect
Mater Des
The influence of high R ratio on mild and sharp notched and unnotched fatigue behaviour of 1045 steel with three different heat treatments
Int J Fatigue
Gigacycle fatigue data sheets for advanced engineering materials
J Sci Technol Adv Mater
Bump extraction algorithm for variable amplitude fatigue loading
Int J Fatigue
Energy-based prediction of low-cycle fatigue life of BS 460B and BS B500B steel bars
Mater Des
Fatigue analysis under variable amplitude loading using an energy parameter
Int J Fatigue
Fatigue failure of structural steel – analysis using fracture mechanics
World Academy of Science Engineering and Technology
Finite element based vibration fatigue analysis for a new free piston engine component
Arab J Sci Eng
Fatigue behaviour analysis of mechanical components subject to random bimodal stress process: frequency domain approach
Int J Fatigue
Generation of correlated stress time histories from continuous turbulence power spectral density for fatigue analysis of aircraft structures
Int J Fatigue
On cyclic stressstrain behaviour and low cycle fatigue life
Mater Des
Cited by (5)
STUDY AND PREDICTION OF THE FATIGUE LIFE OF AISI 1045 STEEL STRUCTURES UNDER ROTATIONAL BENDING STRESSES
2022, UPB Scientific Bulletin, Series D: Mechanical EngineeringElasticity modulus variation of the AISI SAE 1045 steel subjected to corrosion process by chloride using tension test destructive
2020, IOP Conference Series: Materials Science and EngineeringThe need to generate a force time history towards life assessment of a coil spring
2017, Journal of Mechanical EngineeringPrediction of fatigue life of welding tool in friction stir welding of AA6061-T6
2016, International Journal of Advanced Manufacturing TechnologyDurability simulation analysis of jet pipe servovalve
2015, Xibei Gongye Daxue Xuebao/Journal of Northwestern Polytechnical University