Multi-Jackbolt Tensioner Type Expansion Bolts for Marine Applications

2009 ◽  
Author(s):  
Stephen J. Busalacchi
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Shear Test ◽  
Marine Environments ◽  
Interference Fit ◽  
Thrust Bearings ◽  
Removal Time ◽  
Load Carrying ◽  
Marine Applications ◽  
Element Method

This paper introduces and discusses the multi-jackbolt tensioner (MJT) type expansion bolt with split expanding sleeve as a replacement to standard fitted or interference fit bolts that are widely used within industry, including navy and marine environments. For marine uses, applications include shaft and propulsion coupling bolting as well as on anchoring and positioning bolting often required for most line shaft bearings, thrust bearings, and steering gears. Both a Finite Element Method (FEM) study and a shear test were recently performed to confirm superior load carrying ability as compared to standard fitted bolts. Further, results of these tests, installation / removal time comparisons, and calculated costs savings are presented here for consideration.

Analysis of Step Interference Fit of the High Speed Motorized Spindle with Finite Element Method

2004 ◽  
Vol 471-472 ◽  
pp. 844-849 ◽  
Author(s):  
Ping Ma ◽  
Cheng Xiang Liao ◽  
M.L. Duan ◽  
J.K. Li ◽  
D.N. Li ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
High Speed ◽  
Three Dimensional ◽  
Internal Surface ◽  
Three Dimensional Model ◽  
Motorized Spindle ◽  
Interference Fit ◽  
Balance Accuracy ◽  
Element Method

Balance for high speed motorized spindle is most important, it will influence the dynamic behavior of the high speed machine tools. In this paper, the GD-IV high speed spindle is introduced. In order to improve its balance accuracy, the step interference fit is developed to connect the rotor and the shaft. The interference fitted assembly has been modeled theoretically, the analysis highlights that the tolerance of the interference fit consists of the static section and dynamic section, the static section is determined by the transmitting torque while the dynamic section is determined by the centrifugal force. The Calculation of interference fit for the GD-IV spindle shows that the dynamic section is about 4.5 times larger than the static. Furthermore, the three dimensional model of the step interference fit between the shaft and the rotor has also been built up with finite element method and the stress distribution on the mating surface has been calculated. The results show that the maximum stress occurring near the chamfer region of the internal surface of the rotor is up to 235 MPa lower than the permissible material stress 278 MPa, so that the design of the step interference fit is reliability and safety.

Root iterative method for static performance analysis of aerostatic thrust bearings with multiple pocketed orifice-type restrictors based on ANSYS

2019 ◽  
Vol 72 (1) ◽  
pp. 165-171
Author(s):  
Yangong Wu ◽  
Zheng Qiao ◽  
Jiadai Xue ◽  
Yutao Liu ◽  
Bo Wang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Iterative Method ◽  
Mass Conservation ◽  
Numerical Approach ◽  
Rotary Table ◽  
Content Type ◽  
Thrust Bearings ◽  
Static Performance ◽  
Element Method

Purpose The purpose of this paper is to present a novel numerical approach to analyze the static performance of aerostatic thrust bearings by adopting a general finite element method calculation program. Design/methodology/approach The characteristics of a gas film are described by the Reynolds equation and the pressure distribution is solved using the finite element method. A root iterative method is proposed to meet the requirement of the mass-conservation law because multiple pocketed orifice-type restrictors are treated as a series of special boundary conditions. Findings The static performance of a rotary table using aerostatic thrust bearings, including load carrying capacity and stiffness, can be predicted by the method; moreover, it can be further confirmed through experiments on the designed rotary table. Originality/value The method combining the finite element and root iterative methods is highly accurate and has a low time-cost for analyzing aerostatic thrust bearings with multiple pocketed orifice-type restrictors.

scholarly journals The Assessment of the Technical Condition of Complex Fatigued Load-Carrying Structures

2021 ◽  
Vol 11 (6) ◽  
pp. 2449
Author(s):  
Robert Misiewicz ◽  
Jędrzej Stanisław Więckowski
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Experimental Research ◽  
Technical Condition ◽  
Research Approach ◽  
The Finite Element Method ◽  
Research Techniques ◽  
Main Emphasis ◽  
Load Carrying ◽  
Element Method

This article presents a research approach that enables the assessment of the technical condition of complex technical objects. The main emphasis is placed on the load-carrying structures of these objects. The procedure applying experimental research techniques and computer computations using the finite element method is described. The combination of the two techniques assesses the technical condition of the structure. The described approach is presented using the example of two objects.

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