Plastics pipes for the conveyance of fluids under pressure. Miner's rule. Calculation method for cumulative damage

2015 ◽  
Keyword(s):  
Calculation Method ◽  
Cumulative Damage ◽  
Miner’S Rule ◽  
Miner's Rule

EXPLORATION OF CUMULATIVE DAMAGE EVOLUTION UNDER VARIABLE AMPLITUDE FATIGUE LOADING BASED ON WÖHLER CURVE

2021 ◽  
Author(s):  
RUI MIRANDA GUEDES
Keyword(s):  
Polymer Matrix Composites ◽  
Research Work ◽  
Fatigue Loading ◽  
Cumulative Damage ◽  
Damage Functions ◽  
Simple Assumption ◽  
Variable Amplitude ◽  
Stress Levels ◽  
Miner’S Rule ◽  
Miner's Rule

How to predict the residual strength of polymer matrix composites (PMCs) after a fatigue cycle at multiple stress levels, based on the fatigue or Wöhler (S-N) curves, remains unsatisfactorily tackled. The Miner’s Rule is a widespread example of a simple way to account for damage accumulation under different fatigue cycles. Under certain combinations of stress levels, Miner’s Rule accurately predicts the lifetime of PMCs, but it fails in other cases. The reason is the simple assumption of linear cumulative damage, not accounting for sequence effects in the loading history. Several researchers have proposed modifications to Miner’s Rule. However, due to its simplicity, Miner’s Rule is still used by structural designers. Recent research work proposed compatibility conditions for fatigue damage functions in the S–N plane, leading to a simple model that fulfils those conditions contrary to the previous models, the Miner’s Rule and the Broutman and Sahu linear model. These models predict fatigue life at variable amplitude loading based on constant amplitude fatigue data. Forcibly, the analytical form of SıN influences the model lifetime predictions. Experimental data obtained in the literature serves to illustrate the models' predictions at different loading conditions. Although this work focused on composite materials, we foresaw extension to other materials.

Fatigue Design of Machine Elements Under Cumulative Damage Effect, Using Bagci’s Fatigue Failure Surface Line

1984 ◽  
Vol 106 (4) ◽  
pp. 466-475
Author(s):  
C. Bagci
Keyword(s):  
Fatigue Life ◽  
Fatigue Strength ◽  
Material Properties ◽  
Cumulative Damage ◽  
Damage Effect ◽  
Stress Effect ◽  
Mean Stress ◽  
Fatigue Design ◽  
Miner’S Rule ◽  
Miner's Rule

A thorough review of the state-of-the-art of determining fatigue life of machine and structural members considering cumulative damage effect under varying stress amplitudes is given. Among the many proposed theories, Miner’s linear damage rule is seen to be as reliable as any other rule alleged to be an improvement for predicting fatigue life under cumulative damage effects. Its simplicity and amenability for easy modification have in fact been the basis for some other theories and used in design codes. In its original form, Miner’s rule, however does not account for fatigue strength reducing factors. Observing fatigue data on the effects of fatigue strength reducing factors, the article offers a modified form of the Miner’s rule to consider the effects of fatigue strength reducing factors, such as the notch, reliability, surface finish, size, and environmental factors. The mean stress effect and material properties are incorporated utilizing Bagci’s mean stress line and the S-N diagram. The safe fatigue life of a component subjected to stresses of varying magnitudes becomes Ns=df/∑i=1s(αi/10zi) where zi=A{B−log(pig/Rf)+log[1−(pi/mi)r]} in the ith block of stress range, Rf being the resultant of fatigue strength reducing factors; A, B, g are parameters defined by material properties, pi is the ratio of the basic alternating stress times the factor of safety (the failure value) to the yield strength of the material, and mi is the slope of the load line in the ith block of loading. Design charts for zi for steel and aluminum alloys for cases with and without basic mean stress for r=4 are given. Numerical examples are included. Therefore, the article offers the most general form of the Miner’s rule for designers’ use for fatigue design considering cumulative damage effect.

Fatigue Strength Study on Different Structure Type of Hatch Corner

2011 ◽  
Vol 233-235 ◽  
pp. 2580-2583
Author(s):  
Yong He Xie ◽  
Wei Wang ◽  
Heng Zhang
Keyword(s):  
Fatigue Strength ◽  
Scale Effect ◽  
Hot Spot ◽  
Structure Type ◽  
Cumulative Damage ◽  
Hot Spot Stress ◽  
Fatigue Design ◽  
Miner’S Rule ◽  
Curve Method ◽  
Miner's Rule

The fatigue strength study of the hatch corner is carried out ,based on the S-N curve method and the assumption of the linear cumulative damage of Palmgren-Miner's rule, using the hot spot stress method. Study on the effect of the structure different type to the fatigue strength of the hatch corner is carried out through changing its construction details and thickness. By comparing, the reasonable structure is obtained, and the scale effect should be put into consideration in fatigue design.

scholarly journals Discussion of Miner’s Rule on Type 304 Austenitic Stainless Steel at 288 C in Air

2005 ◽  
Author(s):  
Makoto Hayashi
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Cumulative Damage ◽  
304 Stainless Steel ◽  
Random Loads ◽  
304 Austenitic Stainless Steel ◽  
Miner’S Rule ◽  
Cumulative Fatigue Damage ◽  
Miner's Rule ◽  
Type 304

The surface worked type 304 stainless steel exhibits an extraordinary behavior when subjected random fatigue load. In this study the effect of load history on the cumulative damage was examined. The random loads are 1) two step increasing stresses, 2) two step decreasing stresses, 3) repeated high and low step stresses, 4) repeated low and high step stresses, and 5) gradually increasing stresses. In any cases the cumulative damage calculated according to Miner’s rule remarkably exceeded 1.0, especialy for the gradually increasing stresses. In order to survey the mechanism, the elastic and plastic strain behaviors were studied. The extraordinal cumulative fatigue damage could be explained by the remarkable fatigue hardening behavir of austenitic stainless steel.

Nonlinear cumulative damage model and application to bridge fatigue life evaluation

2017 ◽  
Vol 21 (9) ◽  
pp. 1402-1408
Author(s):  
Huili Wang ◽  
Sifeng Qin ◽  
Yunjie Wang
Keyword(s):  
Fatigue Life ◽  
Damage Mechanics ◽  
Damage Model ◽  
Cumulative Damage ◽  
Life Evaluation ◽  
Cumulative Rate ◽  
Miner’S Rule ◽  
Fatigue Life Evaluation ◽  
Cumulative Damage Model ◽  
Miner's Rule

Fatigue is a damage accumulation process in which material property deteriorates continuously. Fatigue life prediction issues are important for safety. This article aims to develop a nonlinear cumulative damage model. A fatigue damage model based on the continuum damage mechanics is addressed and applied to bridge fatigue life evaluation. First, the bridge nonlinear cumulative damage model based on damage mechanics is propounded and equivalent effective stress range is given. Then, the effects of the main parameter in the model are analyzed. Finally, Xinghai Bay Bridge is taken as a case study. The results indicate that the damage is increased with the material parameter [Formula: see text] reduced. [Formula: see text] is a material parameter depending on stress amplitude and without physical meaning. If [Formula: see text], the effect of [Formula: see text] is negligible. If [Formula: see text], nonlinear cumulative damage model degrades into Miner’s rule and effect of [Formula: see text] to structural damage is maximum. The cumulative damage curve calculated by the nonlinear cumulative damage model is nonlinear, with a low cumulative rate initially but a very high cumulative rate at the end of the design life, whereas the Miner’s rule is linear. The nonlinear cumulative damage model can reflect actual damage process, while Miner’s rule is pessimistic.

A Comparison of Fracture Mechanics and S–N Curve Approaches in Designing Drill Pipe

1992 ◽  
Vol 114 (3) ◽  
pp. 205-211 ◽  
Author(s):  
A. Ertas ◽  
G. Mustafa ◽  
O. Cuvalci
Keyword(s):  
Fracture Mechanics ◽  
Fatigue Damage ◽  
Drill Pipe ◽  
Ball Joint ◽  
Marine Riser ◽  
Deep Drilling ◽  
Miner’S Rule ◽  
Miner's Rule ◽  
Total Damage ◽  
Dynamic Fatigue

It is well known that the upper ball joint in a marine riser, in deep drilling, can cause fatigue damage in the drill pipe passing through it. A study of fracture mechanics and S–N curve approaches has been undertaken to determine the dynamic fatigue damage in the drill pipe. Miner’s rule is utilized in both methods to determine the total damage. The results of both methods are compared.

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