Fatigue strength of large diameters tension rods with metric cut thread

2021 ◽  
Author(s):  
Georgios Skarmoutsos ◽  
Mathias Euler ◽  
Ulrike Kuhlmann
Keyword(s):  
Fatigue Strength ◽  
Structural Design ◽  
Failure Strain ◽  
Fatigue Tests ◽  
Strain Gauges ◽  
Safe Side ◽  
Complete Failure ◽  
Concentration Factors ◽  
Thread Root ◽  
The University

<p>The present paper deals with the fatigue strength of large diameters tension rods with metric, cut thread of S460N steel grade. In total 36 fatigue tests equally categorised to 4 experimental series with two varying parameters (i) size diameter, M68 and M100, and (ii) surface treatment, hot-dip galvanized or as-rolled, were performed by the Institute of Structural Design at the Material Testing Institute of the University of Stuttgart. The tests conducted herein for rods of metric, cut threads validated the detail category 50 as well as its factor for size effect, while being slightly on the safe side.</p><p>Additionally, one specimen of M100 as-rolled tension rods, equipped with six miniature strain gauges placed on the thread root of the upper tension rod was tested up to 4,8 MN of quasi-static monotonic tension load- ing until complete failure. Strain concentration factors for the thread root of the M100 tension rod were calculated.</p>

Low-Cycle Fatigue of Large-Diameter Bolts

1967 ◽  
Vol 89 (1) ◽  
pp. 53-60 ◽  
Author(s):  
A. L. Snow ◽  
B. F. Langer
Keyword(s):  
Fatigue Strength ◽  
Yield Strength ◽  
Low Cycle Fatigue ◽  
Large Diameter ◽  
Fatigue Curve ◽  
Fatigue Tests ◽  
Strength Reduction ◽  
Additional Information ◽  
Thread Root ◽  
Reduction Factors

New constant-deflection amplitude fatigue data on bolting materials are presented. The relationship of cyclic yield strength to static yield strength is examined. Several series of full-size stud fatigue tests are analyzed and compared to the basic failure curve to obtain experimental fatigue strength reduction factors for bolts and studs. The variation of fatigue strength reduction factors with thread root radius, stud size, thread taper, and other variables is noted. A new design fatigue curve for bolts is proposed which reflects the additional information available at the present time.

scholarly journals Effect of micro-notches on fatigue strength of electrodeposited nanocrystalline nickel thin films

2018 ◽  
Vol 165 ◽  
pp. 04011
Author(s):  
Keisuke Tanaka ◽  
Yuta Murase ◽  
Hirohisa Kimachi
Keyword(s):  
Thin Films ◽  
Fatigue Strength ◽  
Fatigue Limit ◽  
Stress Ratio ◽  
Fatigue Crack Initiation ◽  
Fatigue Tests ◽  
Fine Grained ◽  
Nickel Thin Films ◽  
Nano Crystalline ◽  
Fictitious Crack

The effect of micro-notches on the fatigue strength of nickel thin films was studied. Two types of thin films with 10 μm thickness were produced by electrodeposition using sulfamate solution without and with brightener: ultra-fine grained film (UFG) with the grain size of 384 nm and nano-crystalline grained film (NCG) with that of 17 nm. Micro-sized notches introduced by FIB had the width of 2 μm and various depths from 8 to 150μm. Fatigue tests were conducted under the stress ratio of 0.1. The fatigue strength decreased with increasing depth of notches. NCG had much higher strength than UFG compared at the same notch depth. Notches as small as 8μm did reduce the fatigue strength of both UFG and NCG. The fatigue limit was controlled by the initiation of cracks and no non-propagating crack was observed in specimens fatigued below the fatigue limit. A model of fictitious crack successfully predicted the reduction of the fatigue limit due to micro-notches. The characteristic crack length of NCG was much smaller than the UFG, while the fatigue strength of defect-free NCG was larger than that of UFG. SEM observation of fracture surfaces was conducted to reveal micromechanisms of fatigue crack initiation.

Effect of Plasma Cutting on the Fatigue Resistance of Fe510 D1 Steel

1999 ◽  
Vol 122 (1) ◽  
pp. 141-145 ◽  
Author(s):  
M. Chiarelli ◽  
A. Lanciotti ◽  
M. Sacchi
Keyword(s):  
Fatigue Resistance ◽  
Low Carbon Steel ◽  
Physical And Mechanical Properties ◽  
Research Programme ◽  
Fatigue Tests ◽  
Automatic Process ◽  
Plasma Cutting ◽  
Low Carbon ◽  
The University

The paper describes the results of a research programme, carried out at the Department of Aerospace Engineering of the University of Pisa, for the assessment of the influence of plasma cutting on the physical and mechanical properties of Fe510 D1, a low carbon steel widely used in carpentry. The activity started by observing that several industries rework plasma cut edges, particularly in the case of fatigue structures, in spite of the good quality of the plasma cut edges in a fully automatic process. Obviously, reworking is very expensive and time-consuming. Comparative fatigue tests demonstrated that the fatigue resistance of plasma cut specimens in Fe510 steel was fully comparable to that of milled specimens, as the consequence of the beneficial residual stresses which formed in the plasma cut edges. [S0094-4289(00)02201-5]

Monitoring of Internal Damage of Glass Fibre Reinforced Composite Components Using Strain Measurements with Strain Gauges and Fibre Optic Sensors

2013 ◽  
Vol 486 ◽  
pp. 58-61 ◽  
Author(s):  
Ivo Černý
Keyword(s):  
Fatigue Strength ◽  
Glass Fibre ◽  
Shear Failure ◽  
Dynamic Stiffness ◽  
Strain Gauges ◽  
Shear Stresses ◽  
Fibre Optic ◽  
Internal Damage ◽  
Manufacture Process ◽  
Glass Fibre Reinforced

Glass fibre reinforced polymer (GRP) composites are perspective materials for manufacture of components in different machinery applications. Favourable characteristics of these materials include very high specific strength, ratio of static and dynamic stiffness, particularly beneficial in dynamically loaded structures, and potentially excellent fatigue strength provided that there are no latent internal imperfections, occurring usually in the manufacture process. Defects like insufficient wet-out of glass fibres by resin result in significant reduction of static and fatigue strength in shear. If the component thickness is high and it is loaded by bending, considerable shear stresses occur in the neutral plane, which can cause premature shear failure of the component. Results of static and fatigue tests in bending of full-scale models of longitudinal frames of railway freight vehicle bogies, manufactured from GRP polyester composites, are shown and analysed in the paper. Surface strains measured using strain gauges were monitored during the component loading, its continuous damage and were analysed. The results are in a good agreement with the subsurface strains evaluated using fibre optic sensors embedded in the component during the manufacture process. Asymmetry of strains, both internal and surface, was connected with internal defects and consequently reduced strength. On the contrary, very good fatigue resistance was characteristic for components, where strain values were symmetrical.

scholarly journals Learning based on the project entitled "Design and construction of a wooden bridge"

2016 ◽  
Vol 6 (2) ◽  
pp. 135
Author(s):  
Cristina Barris ◽  
Lluís Torres ◽  
Enric Simon
Keyword(s):  
Structural Design ◽  
Failure Load ◽  
Theoretical Calculations ◽  
Project Based Learning ◽  
Course Content ◽  
The Third ◽  
Material Optimization ◽  
Engineering Degree ◽  
The University ◽  
Design And Construction

This article presents the results of a case involving the application of project-based learning carried out with students in the Mechanical Engineering degree program at the University of Girona. The project, entitled “Design and construction of a wooden bridge”, was conducted at the Polytechnic School in the third-year Structures course. This project required students to address, consider and solve different problems related to the resistance of materials, structural calculations, material optimization and structural design. The project also included the building of the bridge based on the calculations made, thus enabling the students to verify the suitability of the theoretical calculations as compared to real results. Finally, a competition was held to reward those teams who obtained the best ratio between the failure load and the weight of the bridge. The main conclusion observed from the implementation of only two editions of this project is the acquisition of the different proposed competences (both specific and cross-curricular) by the students. Finally, it was interesting to note that after completing the activity, the students were observed to be more motivated by the course content.

Influence of Inner Surface Defects on the Fatigue Strength of Pipe Subjected to Cyclic Internal Pressure

1978 ◽  
Vol 100 (4) ◽  
pp. 360-368
Author(s):  
Y. Yazaki ◽  
S. Hashirizaki ◽  
S. Nishida ◽  
C. Urashima
Keyword(s):  
Fatigue Strength ◽  
Internal Pressure ◽  
Test Specimen ◽  
Surface Defects ◽  
Fatigue Crack Initiation ◽  
Internal Surface ◽  
Fatigue Tests ◽  
Inner Surface ◽  
Surface Notch ◽  
Medium Diameter

Cyclic internal oil pressure fatigue tests were carried out on medium-diameter ERW pipes of API 5LX - X60 in an attempt to determine the influence of surface defects on the fatigue strength. Experimental factors investigated were the depth and location of internal surface notch in relation to the axis of pipe. The specimen was subjected to cyclic internal pressure, the cyclic rate being 0.3–0.5 Hz. During the test, Acoustic Emission (AE) techniques were applied to detect the fatigue crack initiation. Along with the aforementioned fatigue tests, pulsating tension fatigue tests were carried out on specimens with the same surface notches as the cyclic internal pressure fatigue test specimen.

The effect on the fatigue strength of bone cement of adding sodium fluoride

2001 ◽  
Vol 215 (2) ◽  
pp. 251-253 ◽  
Author(s):  
C Minari ◽  
M Baleanil ◽  
L Cristofolini ◽  
F Baruffaldi
Keyword(s):  
Fatigue Strength ◽  
Bone Cement ◽  
Sodium Fluoride ◽  
Biomedical Applications ◽  
Cement Mantle ◽  
Fatigue Tests ◽  
Fatigue Performance ◽  
Bone Cements ◽  
The Novel ◽  
Pmma Bone Cement

New bone cements that include several additives are currently being investigated and tested. One such additive is sodium fluoride (NaF), which promotes bone formation, facilitating implant integration and success. The influence of NaF on the fatigue performance of the cement as used in biomedical applications was tested in this paper. In fact fatigue failure of the cement mantle is a major factor limiting the longevity of a cemented implant. An experimental bone cement with added NaF (12wt%) was investigated. The fatigue strength of the novel bone cement was evaluated in comparison with the cement without additives; fatigue tests were conducted according to current standards. The load levels were arranged based on a validated, statistically based optimization algorithm. The curve of stress against number of load cycles and the endurance limit were obtained and compared for both formulations. The results showed that the addition of NaF (12 wt %) to polymethylmethacrylate (PMMA) bone cement does not affect the fatigue resistance of the material. Sodium fluoride can safely be added to the bone cement without altering the fatigue performance of the PMMA bone cement.

Effect of Processing Layer on Fatigue Strength of Extruded AZ61 Magnesium Alloy

2013 ◽  
Vol 577-578 ◽  
pp. 429-432 ◽  
Author(s):  
Yukio Miyashita ◽  
Kyohei Kushihata ◽  
Toshifumi Kakiuchi ◽  
Mitsuhiro Kiyohara
Keyword(s):  
Fatigue Crack ◽  
Fatigue Life ◽  
Fatigue Strength ◽  
Magnesium Alloy ◽  
Crack Initiation ◽  
Crack Growth ◽  
Fatigue Crack Initiation ◽  
Fatigue Tests ◽  
Crack Growth Resistance ◽  
Az61 Magnesium Alloy

Fatigue Property of an Extruded AZ61 Magnesium Alloy with the Processing Layer Introduced by Machining was Investigated. Rotating Bending Fatigue Tests were Carried out with the Specimen with and without the Processing Layer. According to Results of the Fatigue Tests, Fatigue Life Significantly Increased by Introducing the Processing Layer to the Specimen Surface. Fatigue Crack Initiation and Propagation Behaviors were Observed by Replication Technique during the Fatigue Test. Fatigue Crack Initiation Life of the Specimen with the Processing Layer was Slightly Longer than that of the Specimen without the Processing Layer. Higher Fatigue Crack Growth Resistance was also Observed when the Fatigue Crack was Growing in the Processing Layer in the Specimen with the Processing Layer. the Longer Fatigue Life Observed in the Fatigue Test in the Specimen with the Processing Layer could be Mainly due to the Higher Crack Growth Resistance. it is Speculated that the Fatigue Strength can be Controlled by Change in Condition of Machining Process. it could be Effective way in Industry to Improved Fatigue Strength only by the Cutting Process without Additional Surface Treatment Process.

Fatigue of Autofrettaged Thick Tubes: Closed and Open Ended; As-Received and Honed

1983 ◽  
Vol 105 (3) ◽  
pp. 195-201 ◽  
Author(s):  
W. N. Findley ◽  
R. M. Reed
Keyword(s):  
Fatigue Strength ◽  
Fatigue Tests ◽  
Steel Tubes

Results of fatigue tests are presented for thick tubes of 32.3 mm (1.27 in) ID and wall ratio of 2.5 of SAE 4333 steel. Tubes having both as-received and honed bores were autofrettaged to three different degrees. Results are given for both open-ended and closed-ended autofrettage. Autofrettage increased the fatigue strength as much as 107 percent. Over autofrettage and open-ended autofrettage produced results not much different from closed-ended normal autofrettage. Under autofrettage causing half the change in diameter of normal autofrettage produced 21 percent less fatigue strength than normal autofrettage.

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