Three-Dimensional Strip Element Method And Its Simulation Of Hot Plate And Strip Rolling Process

Shape and profile are the important quality indexes of rolled plate and strip, and shape control is the key technology of plate and strip mills. With the development of shape control technology, shape theory is paid bigger attention day by day and studied deeply. In shape theory, the three-dimensional deformation theory of plate and strip rolling is an important and difficult study content. With the continuous development of shape control technology and shape theory of cold rolled strip, and the continuous enhancement of the demand to the product quality of hot rolled plate and strip, people transfer their attentions to shape theory research and shape control technology exploitation of hot rolled plate and strip, shape and profile have been the primary quality indexes and the important factors of deciding the market competitive power of hot rolled plate and strip, and the three-dimensional deformation theory of hot rolled plate and strip have also been the leading edge and the focus of current research and exploitation.On the basis of the streamline strip element method, to the character that hot rolled strip and thick plate are thicker, a new strip element method ——the strip layer method is put forward to simulate the three-dimensional deformations of plate and strip rolling process. The rolling deformation zone is divided into a number of layers along the altitudinal direction of plate and strip, every layer plate (strip) is divided into a number of streamline strip elements along metal flow traces, and the streamline strip elements are mapped into the corresponding rectangle strip elements for analysis and computation. The longitudinal distribution model of metal lateral displacement is constructed to be a quartic curve, its lateral distribution is expressed as the three-power spline function, and its altitudinal distribution is fitted to be a parabolic curve. Based on the flow theory of plastic mechanics, the three-dimensional deformations and stresses of deformation zone are analyzed and formulated. Compared with the streamline strip element (SSEM), the strip layer method (SLM) consider the uneven distributions of stresses and deformations along the altitudinal direction, and realizes accurate analysis and computation. The simulating examples of hot strip rolling and thick plate rolling indicate that the method and the model are in accord with facts, and provide a new reliable engineering-computation method for a three-dimensional mechanics simulation of plate and strip rolling process. On the basis of the SSEM, a new method—the stream surface strip element method (SSSEM) for simulating the three-dimensional deformations of plate and strip rolling process is put forward. The rolling deformation zone is divided into a number of stream surface (curved surface) strip elements along metal flow traces, and the stream surface strip elements are mapped into the corresponding plane strip elements for analysis and computation. The longitudinal distributions of the lateral displacement and the altitudinal displacement of metal are respectively constructed to be a quartic curve and a quadratic curve, the lateral distributions of them are expressed as the third-power spline function, and the altitudinal distributions of them are fitted to be the quadratic curve. From the flow theory of plastic mechanics, the three-dimensional deformations and stresses of the deformation zone are analyzed and formulated. Compared with the SLM, the SSSEM takes into account the altitudinal displacement of metal and its uneven distributions along altitudinal direction, its approximations and simplifications are fewer, its derivation is simpler, and it is a new three-dimensional strip element method whose theory is more and whose analysis and computation are more concise. The simulation examples indicate that the SSSEM is better in accord with facts, has a wider range of application, and provide a new reliable engineering-computation method for the three-dimensional mechanics simulation of plate and strip rolling process.On the SSSEM...