Papers by Author: Yan Li He

Abstract: The influence of chip formation technology on the simulation of machining unidirectional fiber reinforced polymer composite (FRP) is investigated. Two-dimensional macro-mechanical FE model was developed for orthogonal machining. Tsai-Hill failure criterion was implemented in VUMAT Abaqus subroutine. Two different chip formation technologies were simulated, analyzed and compared with experiment in literature. The results show that chip formation technology makes a difference in FRP machining simulation for various cutting conditions. Though chip shape, cutting forces and sub surface damages predicted by ALE model are more reasonable than that by element deletion model, predictions in both models are not satisfactory due to inherent limitations associated with the macro mechanical FE model and Tsai-Hill damage criterion.

Abstract: The reconfigurability of Manufacturing Execution System (MES) means that it can adapt to different manufacturing environment and application requirements rapidly and easily. A Reconfigurable MES Model (RMM) is discussed with a hierarchical architecture including Production Object Level, Business Activity Level, Business Function Level and Organization Level. The elements of each level are defined, and the implementation mechanisms of reconfigurations are analyzed in detail. Finally, an example is presented to prove the validation of RMM.

Abstract: In this paper，according to the shell theory , model are developed to predict delamination damage in the drilling process. Finally, we will get theoretical delamination factor and complete the prediction of the delamination damage area. The known references didn’t find similar model of predicting delamination damage. Therefore, it is new method. With the drilling process experimental contrast，the model is more effective for the prediction of delamination of the carbon fiber composite materials.

Abstract: A two-dimensional macro-mechanical finite element (FE) model is developed to study the orthogonal cutting process of CFRP unidirectional laminate by the finite element software ABAQUS. The CFRP laminate is defined as an equivalent orthotropic, homogeneous single-phase material. On the basis of composite unidirectional laminate plane stress-strain and strength theory, the author adopts Hashin progressive damage criteria in the FE model. Based on the results of finite element simulation, the changes of cutting force in the chip formation process of CFRP laminate are analyzed, the Hashin damage in the cutting process and the influences of fiber orientation on cutting force, chip formation mechanism and sub-surface damage are explored as well. The comparison between this paper and previous related research shows that the results have a reasonable agreement with the previous achievements.

Abstract: In competitive and uncertain global business environment, manufacturing enterprises must frequently expand manufacturing capacity to respond effectively and quickly to satisfy customer needs. Outsourcing manufacturing through subcontract is an effective approach for this purpose. This paper presents a process collaboration oriented outsourcing manufacturing execution framework, which integrates the functions of manufacturing execution system (MES)inside enterprise and collaborative manufacturing system across enterprises. With the collaborative working environment based on multi agent system, the framework can support enterprises to establish optimum production schedule with due date constraint, construct virtual enterprise by outsourcing tasks to partner enterprises, and utilize internal and external resources to conduct manufacturing activities with the coordination of workflow system, so as to expand the production capacity and reduce the time to market. A prototype system is implemented and demonstrated with a case study. Introduction

Abstract: Collaborative manufacturing is gaining more and more popularity in the dynamic and global market environment, as raises the requirement of a platform to support the remote resource utilization and distributed process integration for the operation and management of collaborative manufacturing. This paper combines agent and grid workflow technology to construct an integrated application service platform for collaborative manufacturing of discrete part. The grid service is used to encapsulate technological resources to be accessible remotely, while the agent technology is integrated with grid service to encapsulate resources such as machine tools which require local human operation. Grid workflow is applied to model and enact the overall manufacturing process and invoke appropriate grid services dynamically so that manufacturing tasks can be executed in a controlled and distributed manner. Issues of system framework, resource encapsulation and process enactment are discussed, and a case study is present to demonstrate the feasibility.

Abstract: Agent technology is widely employed to construct dynamic, distributed collaborative manufacturing systems in which the individual participating agents contribute to execute different part of the whole manufacturing job, and the final goal is achieved through cooperation. However, the cooperation among agents is based on message exchange, and the system requires additional process control and management mechanism to ensure the operation according to a pre-defined process model. This paper defines the collaborative manufacturing job and related information in domain knowledge model, and applies knowledge based expert system to build software agents for process scheduling and management. The system architecture, components and the implementation methods are discussed. A prototype system is constructed on the basis of JADE agent framework and Jess rule engine and demonstrated with an industry product as a case study.