A new method,the stream surface strip element method,for simulating the three-dimensional deformation of plate and strip rolling process was proposed.The rolling deformation zone was divided into a number of stream su...A new method,the stream surface strip element method,for simulating the three-dimensional deformation of plate and strip rolling process was proposed.The rolling deformation zone was divided into a number of stream surface(curved surface)strip elements along metal flow traces,and the stream surface strip elements were mapped into the corresponding plane strip elements for analysis and computation.The longitudinal distributions of the lateral displacement and the altitudinal displacement of metal were respectively constructed to be a quartic curve and a quadratic curve,of which the lateral distributions were expressed as the third-power spline function,and the altitudinal distributions were fitted in the quadratic curve.From the flow theory of plastic mechanics,the mathematical models of the three-dimensional deformations and stresses of the deformation zone were constructed.Compared with the streamline strip element method proposed by the first author of this paper,the stream surface strip element method takes into account the uneven distributions of stresses and deformations along altitudinal direction,and realizes the precise three-dimensional analysis and computation.The simulation example of continuous hot rolled strip indicates that the method and the model accord with facts and provide a new reliable engineering-computation method for the three-dimensional mechanics simulation of plate and strip rolling process.展开更多
Ice shedding problems have severely threatened the safety of overhead transmission lines and caused enormous ruptures or failures of the conductors and their accessories.It is of great importance to study the dynamic ...Ice shedding problems have severely threatened the safety of overhead transmission lines and caused enormous ruptures or failures of the conductors and their accessories.It is of great importance to study the dynamic properties of the transmission lines under ice shedding loads.To perform such analysis,the dynamic behavior of two typical strain sections for UHVDC transmission lines under different ice shedding conditions were simulated in this paper.Then,the dynamic response of the key tension plate as well as its buckling properties was analyzed based on the extacted ice shedding results.Finally,laboratory tests were conducted at the China Electric Power Research Institute to assess the critical value of the buckling of the tension plate.The results show that the key tension plate studied in this paper is primarily influenced by the loads along the transmission lines after taking its dynamic response and buckling properties under synthetic ice shedding conditions into consideration.The short-term fluctuation of the tension should be the major focus in tension plate designs.展开更多
基金Sponsored by National Natural Science Foundation of China(50175095)Provincial Natural Science Foundation of Hebei of China(502173)
文摘A new method,the stream surface strip element method,for simulating the three-dimensional deformation of plate and strip rolling process was proposed.The rolling deformation zone was divided into a number of stream surface(curved surface)strip elements along metal flow traces,and the stream surface strip elements were mapped into the corresponding plane strip elements for analysis and computation.The longitudinal distributions of the lateral displacement and the altitudinal displacement of metal were respectively constructed to be a quartic curve and a quadratic curve,of which the lateral distributions were expressed as the third-power spline function,and the altitudinal distributions were fitted in the quadratic curve.From the flow theory of plastic mechanics,the mathematical models of the three-dimensional deformations and stresses of the deformation zone were constructed.Compared with the streamline strip element method proposed by the first author of this paper,the stream surface strip element method takes into account the uneven distributions of stresses and deformations along altitudinal direction,and realizes the precise three-dimensional analysis and computation.The simulation example of continuous hot rolled strip indicates that the method and the model accord with facts and provide a new reliable engineering-computation method for the three-dimensional mechanics simulation of plate and strip rolling process.
基金supported by the Science and Technology Project of the State Grid Corporation of China“Research on Optimization of Typical Tension Insulator String and Quality Improvement of Key Fittings for UHV Transmission Line”(GCB17201900164).
文摘Ice shedding problems have severely threatened the safety of overhead transmission lines and caused enormous ruptures or failures of the conductors and their accessories.It is of great importance to study the dynamic properties of the transmission lines under ice shedding loads.To perform such analysis,the dynamic behavior of two typical strain sections for UHVDC transmission lines under different ice shedding conditions were simulated in this paper.Then,the dynamic response of the key tension plate as well as its buckling properties was analyzed based on the extacted ice shedding results.Finally,laboratory tests were conducted at the China Electric Power Research Institute to assess the critical value of the buckling of the tension plate.The results show that the key tension plate studied in this paper is primarily influenced by the loads along the transmission lines after taking its dynamic response and buckling properties under synthetic ice shedding conditions into consideration.The short-term fluctuation of the tension should be the major focus in tension plate designs.
