Robust fault-sensitive synchronization of a class of nonlinear systems

Aiming at enhancing the quality as well as the reliability of synchronization,this paper is concerned with the fault detection issue within the synchronization process for a class of nonlinear systems in the existence of external disturbances.To handle such problems,the concept of robust fault-sensitive (RFS) synchronization is proposed,and a method of determining such a kind of synchronization is developed.Under the framework of RFS synchronization,the master and the slave systems are robustly synchronized,and at the same time,sensitive to possible faults based on a mixed H /H ∞ performance.The design of desired output feedback controller is realized by solving a linear matrix inequality,and the fault sensitivity H index can be optimized via a convex optimization algorithm.A master-slave configuration composed of identical Chua’s circuits is adopted as a numerical example to demonstrate the effectiveness and applicability of the analytical results.     

Transient temperature fields and residual stress fields of metallic materials under welding

Based on the situation of welding thermal conduction and thermo-elasto-plasticityresearch,Ms paper explores some problems in this field.First,the boundary elementmethod for nonlinear problems is improved by linearization of nonlinear problems and usedin welding thermal conduction analysis.Second,the thermo-elasto-plastic finite elementmethod is used for the welding stress calculation,in which the phase transformation isconsidered by the"equivalent linear expansion coefficient method".The comparison of the calculated results with experimental data shows that themethods provided in this paper are available.