The Tightening of Bolts to Yield and Their Performance Under Load

1986 ◽  
Vol 108 (2) ◽  
pp. 213-221 ◽  
Author(s):  
Ian Chapman ◽  
John Newnham ◽  
Paul Wallace
Keyword(s):  
Fatigue Strength ◽  
Stress Distribution ◽  
Yield Point ◽  
Dynamic Strength ◽  
Bolted Joints ◽  
Bolt Preload ◽  
High Fatigue ◽  
External Loads

The mechanism of tightening bolted joints and the stress distribution in the bolt are analyzed. Measurements were made of static and dynamic strength of joints. It is shown that all bolts behave elastically when external loads are applied to the joint even when the fastener was tightened to its torque-tension yield point. It is shown that joints generally fail when the external loads are sufficient to overcome the bolt preload. Fatigue reesults show that joint fatigue strength increases with preload, and that high fatigue bolts gave an improvement over standard fasteners at all preloads.

LUCEFIN GROUP 20NiCrMo2-2(1.6523), 20NiCrMoS2-2 (1.6526)

Alloy Digest ◽  
2020 ◽  
Vol 69 (12) ◽  
Keyword(s):  
Wear Resistance ◽  
Fatigue Strength ◽  
Physical Properties ◽  
Tensile Properties ◽  
Heat Treating ◽  
Medium Size ◽  
Case Hardening ◽  
Low Carbon ◽  
High Fatigue

Abstract Lucefin Group 20NiCrMo2-2 and 20NiCrMoS2-2 are low-carbon, Ni-Cr-Mo, alloy case-hardening steels that are used in the carburized or carbonitrided, and subsequently quench hardened and tempered, condition. These steels are, in general, used for medium-size case-hardened parts requiring high fatigue strength and wear resistance. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on forming, heat treating, and joining. Filing Code: SA-866. Producer or source: Lucefin S.p.A..

SANBAR 20

Alloy Digest ◽  
1999 ◽  
Vol 48 (8) ◽  
Keyword(s):  
Wear Resistance ◽  
Fatigue Strength ◽  
Tensile Properties ◽  
High Strength ◽  
Heat Treating ◽  
Steel Company ◽  
High Fatigue ◽  
Molybdenum Steel ◽  
Rolled Condition

Abstract SANBAR 20 is a high-strength chromium-molybdenum steel with high-fatigue strength and excellent wear resistance in the as-rolled condition. The primary application is use as integral drill rods. This datasheet provides information on composition, hardness, and tensile properties. It also includes information on forming, heat treating, and machining. Filing Code: SA-501. Producer or source: Sandvik Steel Company.

Surface Cross-linked UHMWPE: A Low Wear Material with Very High Fatigue Strength

2010 ◽  
Vol 25 (3) ◽  
pp. e72
Author(s):  
Ebru Oral ◽  
Bassem Ghali ◽  
Shannon Rowell ◽  
Brad Micheli ◽  
Orhun Muratoglu
Keyword(s):  
Fatigue Strength ◽  
High Fatigue ◽  
Low Wear ◽  
Very High

Accurate Evaluation of Bolt and Clamped Members Stiffnesses Of Bolted Joints

2021 ◽  
Author(s):  
Rashique Iftekhar Rousseau ◽  
Abdel-Hakim Bouzid ◽  
Zijian Zhao
Keyword(s):  
Finite Element ◽  
Joint Stiffness ◽  
Element Model ◽  
Fe Analysis ◽  
Bolted Joints ◽  
Analytical Models ◽  
Fe Modeling ◽  
Bolted Joint ◽  
A New Technique ◽  
External Loads

Abstract The axial stiffnesses of the bolt and clamped members of bolted joints are of great importance when considering their integrity and capacity to withstand external loads and resist relaxation due to creep. There are many techniques to calculate the stiffnesses of the joint elements using finite element (FE) modeling, but most of them are based on the displacement of nodes that are selected arbitrarily; therefore, leading to inaccurate values of joint stiffness. This work suggests a new method to estimate the stiffnesses of the bolt and clamped members using FE analysis and compares the results with the FE methods developed earlier and also with the existing analytical models. A new methodology including an axisymmetric finite element model of the bolted joint is proposed in which the bolts of different sizes ranging from M6 to M36 are considered for the analysis to generalize the proposed approach. The equivalent bolt length that includes the contribution of the thickness of the bolt head and the bolt nominal diameter to the bolt stiffness is carefully investigated. An equivalent bolt length that accounts for the flexibility of the bolt head is proposed in the calculation of the bolt stiffness and a new technique to accurately determine the stiffness of clamped members are detailed.

Assessment of Cryogenic Fatigue Strength of MARK-III LNG Carrier Insulation System

2009 ◽  
Author(s):  
Myung Hyun Kim ◽  
Yoon Pyo Kil ◽  
Min Sung Chun ◽  
Yong Suk Suh ◽  
Wha Soo Kim ◽  
...  
Keyword(s):  
Fatigue Strength ◽  
Dynamic Strength ◽  
Fatigue Loading ◽  
Limited Information ◽  
Insulation System ◽  
Fundamental Study ◽  
Design Guideline ◽  
Oil Companies ◽  
Containment System ◽  
Effective Manner

The importance of dynamic strength characteristics of LNG cargo containment system, various research efforts including dry-drop and wet-drop tests as well as sloshing test have been carried out by GTT, shipyards, oil companies, universities as well as classification societies. However, no explicit consideration with regard to the structural performance of insulation system toward the cryogenic environment is yet given. Besides only limited information regarding experimental procedure and analysis results is shared among stakeholders, and it acts as obstacles for the development of consistent CCS (Cargo Containment System) design criteria in an effective manner. Demand for LNG carriers with increased capacity requires further development of the design technology for LNG cargo tanks to meet the safety requirements due to the larger size LNG tanks. In this study, a systematic experimental research is required for the assessment of fatigue strength at cryogenic environment as well as impact strength of insulation system. The different sized mastic support has been adopted to compare the cryogenic fatigue performance. One of the main challenges in this work is to generalize the test results for use in case of other mastic support sizes. The aim of the study is to investigate the typical failure mode and obtain the S-N data under cryogenic fatigue loading. This study will be used as a fundamental study for the cryogenic fatigue assessment for the LNGC insulation system as well as a design guideline. The fatigue tests of Mark-III insulation system are carried out at room temperature and cryogenic temperature, and considered sloshing effect (R = −10). The load levels have been determined based on ultimate strength of reinforced polyurethane foam 12.2bar.

Effect of Repeated Quenching on the Rotating Bending Strength of SAE52100 Bearing Steel

2012 ◽  
Vol 457-458 ◽  
pp. 1025-1031 ◽  
Author(s):  
Koshiro Mizobe ◽  
Edson Costa Santos ◽  
Takashi Honda ◽  
Hitonobu Koike ◽  
Katsuyuki Kida ◽  
...  
Keyword(s):  
Fatigue Strength ◽  
Bending Strength ◽  
High Strength ◽  
Bearing Steel ◽  
Rolling Contact ◽  
High Wear Resistance ◽  
High Carbon ◽  
Austenite Grain ◽  
High Fatigue ◽  
Rotating Bending

Martensitic high carbon high strength SAE 52100 bearing steel is one of the main alloys used for rolling contact applications where high wear resistance are required. Due to its high fatigue strength, SAE 52100 is recently being used not only for the production of bearings but also shafts. Refining of prior austenite grain through repeated quenching is a procedure that can be used to enhance the material’s strength. In this work, the microstructure of repeatedly quenched SAE 52100 steel and its fatigue strength under rotating bending were investigated. It was found that repeated furnace heating and quenching effectively refined the martensitic structure and increased the retained austenite content. Repeated quenching was found to improve the fatigue strength of SAE 52100.

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