Micro/Nanocrack Propagation and Fatigue Strength Analysis of Gun Barrel

2020 ◽  
Vol 20 (3) ◽  
pp. 843-852
Author(s):  
Junpeng Ren ◽  
Deshi Wang
Keyword(s):  
Fatigue Strength ◽  
Strength Analysis ◽  
Gun Barrel

scholarly journals Fatigue Strength Analysis of S34MnV Steel by Accelerated Staircase Test

2020 ◽  
Vol 10 (1) ◽  
pp. 394-400 ◽  
Author(s):  
I. M. W. Ekaputra ◽  
Rando Tungga Dewa ◽  
Gunawan Dwi Haryadi ◽  
Seon Jin Kim
Keyword(s):  
Standard Deviation ◽  
Fatigue Strength ◽  
Fatigue Limit ◽  
Fatigue Testing ◽  
Reliability Estimation ◽  
Test Method ◽  
Strength Analysis ◽  
Staircase Method ◽  
Staircase Test ◽  
Number Of Cycles

AbstractThis paper presents the reliability estimation of fatigue strength of the material used for crank throw components. The material used for crank throw components is forged S34MnV steel and subsequently heat-treated by normalising and tempering. High cycle fatigue testing under fully reversed cycling (R = −1) was performed to determine the fatigue limit of the material. The staircase test method is used to obtain accurate values of the mean fatigue limit stress until a number of cycles up to 1E7 cycles. Subsequently, the fatigue test results depend strongly on the stress step and are evaluated by the Dixon-Mood formula. The values of mean fatigue strength and standard deviation predicted by the staircase method are 282 MPa and 10.6MPa, respectively. Finally, the reliability of the design fatigue strength in some selected probability of failure is calculated. Results indicate that the fatigue strength determined from accelerated staircase test is consistent with conventional fatigue testing. Furthermore, the proposed method can be applied for the determination of fatigue strength and standard deviation for design optimisation of S34MnV steel.

scholarly journals Fatigue Strength Analysis and Fatigue Damage Evaluation of Roller Chain

Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 847 ◽  
Author(s):  
Ryoichi Saito ◽  
Nao-Aki Noda ◽  
Yoshikazu Sano ◽  
Jian Song ◽  
Takeru Minami ◽  
...  
Keyword(s):  
Fatigue Crack ◽  
Fatigue Strength ◽  
Fatigue Damage ◽  
Fatigue Crack Initiation ◽  
Strength Analysis ◽  
The Finite Element Method ◽  
Roller Chain ◽  
Press Fitting ◽  
The Press ◽  
Static Tensile

This paper deals with the roller chain commonly used for transmission of mechanical power on many kinds of industrial machinery, including conveyors, cars, motorcycles, bicycles, and so forth. It consists of a series of four components called a pin, a bush, a plate, and a roller, which are driven by a sprocket. To clarify the fatigue damage, in this paper, the finite element method (FEM) is applied to those components under three different types of states, that is, the press-fitting state, the static tensile state, and the sprocket-engaging state. By comparing those states, the stress amplitude and the average stress of each component are calculated and plotted on the fatigue limit diagram. The effect of the plastic zone on the fatigue strength is also discussed. The results show that the fatigue crack initiation may start around the middle inner surface of the bush. As am example, the FEM results show that the fatigue crack of the inner plate may start from a certain point at the hole edge. The results agree with the actual fractured position in roller chains used in industry.

Crack morphology models for fracture toughness and fatigue strength analysis

2019 ◽  
Vol 42 (9) ◽  
pp. 1965-1979 ◽  
Author(s):  
Andrea Carpinteri ◽  
Andrea Spagnoli ◽  
Michele Terzano
Keyword(s):  
Fracture Toughness ◽  
Fatigue Strength ◽  
Strength Analysis ◽  
Crack Morphology

scholarly journals Fatigue strength analysis of bogie frames under random loads

2019 ◽  
Vol 11 (9) ◽  
pp. 168781401987801 ◽  
Author(s):  
Qi An ◽  
Hua Zhao ◽  
Peihai Li ◽  
Maohai Fu
Keyword(s):  
Fatigue Strength ◽  
Coordinate System ◽  
Welded Joints ◽  
Strength Analysis ◽  
Node Degree ◽  
International Institute ◽  
Bogie Frame ◽  
Welding Method ◽  
Stress Components ◽  
Time Histories

In this study, a method for analyzing the fatigue strength of a bogie frame under a random load was proposed. Based on the geometric features, a welded joint coordinate system was established to compute the stress components of each node in this coordinate system. With the influence of small amplitude cycles included, based on the corrected S–N curve and a method for calculating the equivalent constant amplitude stress, the node and comprehensive degree of utilization were calculated based on the anti-fatigue design grade of welded joints to evaluate the fatigue strength of a structure under a given lifespan. The FKM and International Institute of Welding methods were used to evaluate the fatigue strength of typical welded joints of a bogie frame. The characteristics of the node degree of utilization under different analytical methods were compared, and the results showed that when the time histories of the three stress components of the nodes had significant non-proportional features, the FKM method obtained conservative results. When the time histories of the three stress components of the nodes were synchronized, the criterion value specified by the International Institute of Welding method was the main factor affecting the distribution characteristics of the node degree of utilization. The analysis based on the International Institute of Welding method can effectively balance the lightweight design and reliability of the structure.

Life Assessment in Fretting Fatigue

2014 ◽  
Vol 618 ◽  
pp. 99-122 ◽  
Author(s):  
Carlos Navarro ◽  
Jesús Vázquez ◽  
Jaime Domínguez
Keyword(s):  
Fatigue Strength ◽  
Detrimental Effect ◽  
Fretting Fatigue ◽  
Life Assessment ◽  
Stress Fields ◽  
Strength Analysis ◽  
Cyclic Loads ◽  
Cyclic Variation ◽  
Contact Conditions ◽  
The Many

Fretting fatigue denotes the detrimental effect on a material arising from the cyclic sliding of two contacting surfaces with small relative displacements between them. One or both of the components in contact may be subject to bulk stresses caused by cyclic loads. The assessment of the fretting fatigue strength and life of any component is a complicated issue due to the many parameters affecting it, the complexity of the stress fields cyclic variation during fretting and the uncertainties associated to the contact conditions. This paper describes some singular aspects of fretting fatigue related to strength analysis and testing, presents a procedure developed by the authors during the last years to estimate the fretting fatigue strength and life and compares the assessment outcomes with the results of tests carried out by different authors.

Stress field and fatigue strength analysis of 135-degree sharp corners based on notch stress strength theory

2015 ◽  
Vol 107 ◽  
pp. 32-44 ◽  
Author(s):  
Wei Shen ◽  
Nigel Barltrop ◽  
Renjun Yan ◽  
Enqian Liu ◽  
Kai Qin ◽  
...  
Keyword(s):  
Fatigue Strength ◽  
Stress Field ◽  
Strength Analysis ◽  
Strength Theory ◽  
Notch Stress ◽  
Sharp Corners
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