The Fiber Reinforced Plastic (FRP) has been widely used in aircraft, spacecraft, watercraft and transportation because of its excellent mechanical characteristics. The fatigue characteristic of the composite laminate of FRP is important guarantee to the structure security and reliability. In this paper, according to the damage mechanical theory, a fatigue damage accumulation model based on stiffness degradation and the corresponding method of fatigue life prediction are presented. The composite material of T300/ epoxy-resin with high performance has been investigated. The tension-tension fatigue tests have been conducted on the composite laminates. The fatigue life prediction of the composite material is presented. It shows a good agreement to the experimental and theoretical results.

Dimensioning work is a considerably important link in the whole Engineering Drawing. For existing completeness testing of dimensioning, correct conclusion can not be drawn in case of multi-closed dimension. This paper mainly discusses the ways how to automatically check up the deficiency and redundancy of the dimensions. This paper presents a new and effective algorithm to test whether the dimensions are redundant or insufficient by means of the graph theory and intelligent search. The dimensions are transformed to non-directed graph, then detects whether they are redundant or insufficient by traversing adjacent matrix of the non-directed graph. The deficiency and redundancy of dimension for multi-views of engineering drawing can be corrected by this algorithm.

An example of the rule-based expert system applied to the fan fault diagnosis is presented. The architecture and function of the fault diagnosis system are introduced. The expression of the fault diagnosis knowledge and the attribute of knowledge base based on the relational database have been studied. The hybrid reasoning technology was applied to the implementation of the diagnosis inference engine in the expert system. The presented fault diagnosis system is easy to modify the knowledge base with the experience accumulated in practice, and it has the advantages of expansibility, portability, concision, and high efficiency.

The curve NC grinding methods in presnet are analyzed. On the basis of this, a new curve NC grinding method―region contact grinding (RCG) method is proposed. With this method, the contact point between grinding wheel and workpiece can be controlled in the given contact zone. The problom of grinding wheel's distortion which is produced by contact point excessively deviating from symmetrical central plane of grinding wheel can be overcome. In order to the grinding mode, a new interpolation algorithm―region equiangular linear interpolation (RELI) is proposed. Namely, in terms of the convex-concave property of processing curve, some grinding regions are divided. In each grinding region, the grinding wheel's swing angle within each interpolation cycle is evenly distributed. Thereby, in the process of grinding a convex-concave curve, grinding wheel's contact points totally locate in the range of contact zone angle.

Engineering components and structures in service are generally subjected to the multiaxial complex loads. The approach of critical plane has been widely accepted by most researchers as the best method in the multiaxial fatigue research field. It can be used well in the constant multiaxial fatigue loads, but not in the complex loads. Basis on analyzing characteristics of shear strain on material planes, the concept of weight-averaged maximum shear strain plane is proposed. A procedure is presented to determine the critical plane under multiaxial random loading. The angle values of the planes that experience peak values of maximum shear strains are averaged by employing the weight function, which is assumed to take into account the main factors of influencing the fatigue behavior, e.g. fatigue damage. The proposed algorithm is applied to the multiaxial in- and out-of-phase experiments to assess the correlation between the weight-averaged maximum shear strain direction and the position of the experimental fatigue crack initiation plane.