【正文】 large size statically indeterminate structure with sliding degree of freedom in third dimension ,load distribution can not be determined by deformation patibility condition. Thus new theory basis will be provided by analyzing of contact behaviour and mechanism of sliding pair (such as creep ,force of friction ,integral deformation patibility condition ,etc) .3. 5 Coupling Mechanism and Stability of Multi Physical Fields in Material Processing SystemsIn the wake of system function being more and more diversified , conventional technology limits in material processing machine is being broke through unceasingly ,system structure also bees increasingly plicated ,and system performance bees increasingly multi causal . For example ,any instantaneous state of roller in fast rolling mills is affected by elastic deformation ,plastic flow ,heat transfer process , hydro dynamic lubrication process ,interface physical chemistry molecular state and so on . In addition ,electromechanical coupling in processing system have already gone beyond conventional concept ,for instance ,some singular point phenomenon (such as micro variable can be transformed into macro variable) ,are present ,thus roller operation instability may be led by perturbation[8 ] . Therefore ,this subject will study the interaction mechanism of multi physical field and the influence on processing system stability and processing material quality started with analysis of micro state of executive body.3. 6 Multi Technology Integration and Coalescence of Accurate ControlThe material processing machine ,which operate under the circumstance of extraordinary physical field ,is a plicated large scale system ,and some parameters of the system vary on feasible field boundary 。New Trends and Problems in Material Processing Machine Design Theory Abstract : Based on reviewing the historical background, prospecting for the development trend ,analyzing the plicacy and mechanism and summing up some achievements and experiences in scientific research , several new problems and the possible direction of development in material processing technology and machine are proposed ,such as ,producing new concept materials possessing some specific and extraovdinary properties by means of integrating and coalescing conelative frontier science and technology 。thereby ,to keep under accurate control and adjustment of multi field circumstance ,multi dimension coordination ,multi energy conversion , multi level information transfer ,interface multi process coupling ,etc. is of much significance. Since a variety of multi interaction exists in control model ,it is necessary to establish integration framework of coordination work according to decoupling of control model ,so as to accurate control based on the multi technology integration and coalescence is realized.3. 7 Quasi Reality Design and Concurrent Design Based on Knowledge Innovation SystemsDigitalization and visualization of material processing technology will promote immediately the quality of design, operation and control . Therefore optimization of material processing technology and material processing machine by means of realization of virtual simulation of processing procedure through quasi reality design and concurrent design is one of our pressing study subjects.3. 8 Mechanical Behavior of Special Function Materials in the Extraordinary Physical FieldMany key elements and parts in material processing machine are often under the circumstance of super strong force field ,temperature field ,electronic magnetic field and flow field ,and must have the functions of constructing special physical interface. However ,it is difficult for mon single substance material such as metal ,ceramic polymer ,etc. to have both high index of single property and excellent overall quality. Therefore we need to use certain material with new functions for key position[9 ] ,for instance ,multi dimension function gradient material with ultrahigh physical property ,multi dimension function gradient material with intelligence. For these reasons ,it is necessary to study basic law and mechanism of these kind of function material mentioned above ,for instance ,stress (strain) distribution function ,failure mechanism and design criteria of material under the circumstance of extraordinary physical field ,static (dynamic) stiffness and damping ,digitalization design and visualization design of processing system made of gradient function material ,etc ,so that the general mechanics law of element