scholarly journals Including the normal to shear stresses ratio in fatigue life estimation for cyclic loadings

2019 ◽  
Vol 300 ◽  
pp. 15005
Author(s):  
Marta Kurek
Keyword(s):  
Fatigue Life ◽  
Construction Materials ◽  
Orientation Angle ◽  
Multiaxial Fatigue ◽  
Shear Stresses ◽  
Critical Plane ◽  
Fatigue Life Estimation ◽  
Critical Plane Approach ◽  
Machine Elements ◽  
Theoretical Results

The paper presents the estimation of the fatigue life under multiaxial cyclic loading of two construction materials. The main aim of this paper is to present a new method which allows evaluation of fatigue life during the design and construction phase of machine elements. In paper three well known multiaxial fatigue criteria based on the critical plane approach verified. This paper contains a proposition to define a new way of determining an orientation angle of the critical plane. The comparison between experimental and theoretical results varying the critical plane orientation appears to be satisfactory.

scholarly journals Multiaxial Fatigue Life Calculation Model for Engineering Components in Rolling-Sliding Contact

2018 ◽  
Vol 188 ◽  
pp. 02016
Author(s):  
Robert Basan ◽  
Tea Marohnić
Keyword(s):  
Fatigue Life ◽  
Complex Geometry ◽  
Calculation Model ◽  
Multiaxial Fatigue ◽  
Sliding Contact ◽  
Engineering Practice ◽  
Critical Plane ◽  
Principal Axes ◽  
Critical Plane Approach ◽  
Crack Initiation Criterion

Number of important engineering components and elements such as gears, rollers, bearings operate in conditions of rolling-sliding contact loading. Determination of fatigue lives of such components and elements is very important for engineering practice but remains quite chalenging task due to complex states of stress and strain in the material in the vicinity of contact (multiaxiality, non-proportionality, rotation of principal axes, mean compressive stress) as well as complex contact conditions such as loading amplitude, complex geometry of bodies in contact, type of lubrication, value of coefficient of friction, etc. Proposed fatigue life calculation model for cases of rolling-sliding contact is based on critical plane approach in the form of Fatemi-Socie crack initiation criterion. Developed model was implemented in the case of gears teeth flanks in mesh and compared with results and fatigue lives of gears reported in literature. Good agreement was determined confirming validity of developed model. Further advantage of presented approach and developed model is obtained information on critical location(s) and critical plane(s) orientation which can subsequently be used for estimation of crack shapes in initial phases of their growth and later damage type into which they can be expected to develop.

Fatigue Life Prediction Strategies for High-Heat-Load Components

2010 ◽  
Vol 452-453 ◽  
pp. 789-792
Author(s):  
W.L. Xiao ◽  
H.B. Chen ◽  
J.F. Jin
Keyword(s):  
Fatigue Life ◽  
Heat Load ◽  
Life Prediction ◽  
High Heat ◽  
Multiaxial Fatigue ◽  
Fatigue Life Prediction ◽  
Critical Plane ◽  
Critical Plane Approach ◽  
High Heat Load ◽  
Strain Model

High-heat-load components such as photon shutters and masks made of Glidcop Al-15 are subjected to intense thermal cycles from the X-ray beams at the third generation light sources. This paper presents thermal fatigue life prediction results of high-heat-load components at the beam line front end of Shanghai Synchrotron Radiation Facility (SSRF) under different power conditions. Used in this analysis are four typical multiaxial fatigue life prediction models, i.e. the maximum principal strain model, equivalent vonMises strain model, maximum shear strain model and critical plane approach. Detailed comparisons among them were implemented from various aspects including applicable conditions, physical meanings and resultant veracities. Critical plane approach was finally determined to be more appropriate method for dealing with multiaxial fatigue of high-heat-load components. To obtain the multiaxial stress-strain fields, nonlinear finite element analysis (FEA) was performed with commercial software ANSYS.

New strain energy-based critical plane approach for multiaxial fatigue life prediction

2019 ◽  
Vol 54 (5-6) ◽  
pp. 310-319
Author(s):  
Meng-Fei Hao ◽  
Shun-Peng Zhu ◽  
Ding Liao
Keyword(s):  
Fatigue Life ◽  
Strain Energy ◽  
Equivalent Stress ◽  
Equivalent Strain ◽  
Damage Parameter ◽  
Multiaxial Fatigue ◽  
Critical Plane ◽  
Critical Plane Approach ◽  
Energy Aspect ◽  
Life Predictions

Based on critical plane approach, this article develops a new damage parameter through combing the equivalent strain energy aspect for multiaxial fatigue analysis, which includes no additional fitted parameters and overcomes the deficiency of using only equivalent stress/strain criterion separately under multiaxial loadings. Then, experimental data of GH4169, TC4, Al 7050-T7451 alloys under different loading conditions are applied for model validation and comparison with other four models. Results indicate that the proposed damage parameter yields better multiaxial fatigue life predictions than others.

Damage Mechanics and Critical Plane Approach to Multiaxial Fatigue

2013 ◽  
Vol 592-593 ◽  
pp. 239-245
Author(s):  
Roberto Brighenti ◽  
Andrea Carpinteri
Keyword(s):  
Fatigue Life ◽  
Damage Mechanics ◽  
Crack Nucleation ◽  
Fatigue Loading ◽  
Fatigue Behaviour ◽  
Damage Parameter ◽  
Multiaxial Fatigue ◽  
Critical Plane ◽  
Critical Plane Approach ◽  
Scalar Damage Parameter

The mechanical behaviour of structural components subjected to multiaxial fatigue loading is very important in modern design. Several approaches have been introduced in recent decades to analyse this problem. The so-called critical plane approach, based on the stresses acting on the plane where the crack nucleation is expected to occur, is widely used. This criterion can give us a fatigue damage measurement, which can be used to evaluate fatigue life. On the other hand, fatigue life under general multiaxial stress histories can also be assessed by applying the damage accumulation method. In such a method, a scalar damage parameter is quantified through the damage increments which develop during the fatigue process up to the critical damage value corresponding to the final failure of the structures. The damage increment approach to fatigue has recently been discussed and connected to the classical crack propagation approach. In the present paper, the interpretation of the critical plane approach based on the continuum damage mechanics concepts is examined. In particular, the physical meaning of the critical plane approach is shown, that is, such an approach can be interpreted as a damage method which takes into account the scalar damage parameter evaluated along preferential directions. Finally, the fatigue behaviour of a metallic material under multiaxial cyclic load histories is analysed through the two above approaches.

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