1、翻译部分英文原文Swaged Bolts: Modelling of the Installation Process and Numerical Analysis of the Mechanical Behaviour M. Drean , A.-M. Habraken , A. Bouchar , J.-P. Muzeau LERMES/CUST, Blaise Pascal University, BP 206, 63174 Aubiere Cedex, Franceb M&S, Bat B52/3, Chemin des Chevreuils 1, University of Lieg
2、e, B4000 Liege 1, Belgium Received 29 November 2000; accepted 4 July 2002Abstract: Swaged bolts are an alternative to high strength bolts in steel structures. To clarify the steps of the installation process, numerical modelling has been carried out. The relevant phenomena are described and evaluate
3、d. This numerical calculation accounts for large displacements, large strains, mechanical plasticity and friction contact between the components of swaged bolts. The non-linear nite element code Lagamine designed for the simulation of metal forming processes has been used to provide the stress distr
4、ibutions in the components. 2002 Civil-Comp Ltd. and Elsevier Science Ltd. All rights reserved. Keywords: Swaged bolts; HSFG bolts; Bolt modelling; Installation process; Numerical analysis; Metal forming; Friction contact1. Introduction Swaged bolts are an alternative to high strength friction grip
5、(HSFG) bolts for connections in steelstructures. Because of their automatic installation process, the installed preload is expected to be established with reasonable condence. In Europe, the mechanical knowledge about this fastener raised from tests carried out to qualify the bolts 13. Nevertheless,
6、 some unexpected mechanical results (too low preload value, loss of the preload 2) appeared during installation tests.Therefore, it was decided to use a numerical modelling to describe and to evaluate the inuences of the dierent steps of the installation process on the preload. First, this paper con
7、tains a description of the bolt.Then, the nite element software Lagamine is presented. It allows practical applications with large strains, large rotations and/or large displacements and accounts for friction between elements. After a detailed description of the modelling of each bolt component (geo
8、metry and mechanical characteristics), the calculation results are given. Especially, the way the force is transferred from the hydraulic installation tool into the bolt is explained. Finally, the stress distribution is analysed and related to the low-cycle fatigue behaviour shown during tests.2. Ge
9、neral presentation of swaged bolts2.1. Description of the basic components Like classical HSFG bolts, prestressed swaged bolts are made up of two different components (Fig. 1). The pin acts as a bolt screw with a shank zone chosen according to the thickness of the plates. The collar acts as a nut wh
10、ose threads are created during the installation process. The available pin diameters are 12, 16, 20, 24 and 27 mm. Their geometrical and mechanical characteristics are nearly the same as those of high strength bolts grade 10.9 or A490 1. The main geometrical characteristic of these bolts is the thre
11、ad: a helical groove with a special prole showing a succession of linear and elliptical parts. The at sides are orientated at 20 and at 40 instead of 30 as in a traditional thread. Fig. 1. Collar and pin of a swaged bolt Fig. 2. Installation process2.2. Installation process and advantages of swaged
12、bolts The installation process of swaged bolts is completelydierent from a classical bolt strengthening and it represents the maJor advantage of this type of fastener. It consists of swaging the collar onto the pin with a special hydraulic tool. It is nearly the same installation as rivet installati
13、on. The internal diameter of the hydraulic tool nose (anvil), is smaller than the external diameter of the collar. Therefore, the collar material ows into the pin grooves. This process of installation creates a bond without any gap. So the self-unscrewing of this kind of bolts is nearly impossible.
14、It argues for the use of these fasteners in applications under vibrations (truck body for instance). Moreover, the installation is very fast: less than 30 s per bolt. In civil engineering, where the number of bolts can be large (thousands), it is benecial to minimise the installation time without an
15、y lack of accuracy on the preload. The sequence of the installation process can be divided into four steps (Fig. 2). First (1), the pin is inserted through a prepared hole and the collar is threaded onto the pin using a unique small prethread called tab-lok. Then, the nose assembly of the hydraulic
16、tool is placed over the pintail. The hydraulic pressure makes the tool pull on the pintail and press the plates together (2). The anvil pushes on the collar. Continued pulling on the pintail moves the anvil forward, swaging the collar into the pin grooves. This swaging action lengthens the collar. and develops a permanent clamp force (pr
