Advanced Materials Research Vols. 945-949

Abstract: In recent years, offshore oil & gas industry developed rapidly. Offshore steel structure is the support structure for offshore drilling and production platform, and its welding quality is particularly important in fabrication. This paper aims at the typical welding crack of offshore steel structure, through investigations and experimental analysis, considering the application characteristics of offshore steel structure and site issues, analysis the root causes of welding crack and give the improvement and prevention measures.

Abstract: In view of the geometry, the area of movement and measurement form, put forward the measurement way and method.Laser sensor scans the same area many times in a preset time ,increased the probability of capture the target by optical imaging principle; Tear down analytical expression of the model, system layout by matlab, analysis of the experimental data by Labview. System can satisfy the demand of practical engineering by simple structure, convenient operation, and good stability.

Abstract: This paper studies the structural damage detection and classification problems by using the artificial immune system which has the extremely powerful capabilities of adaptive and the bionic principle between learning and memory. We proposed an artificial immune pattern recognition and structural detection classification algorithm through imitating the immune recognition and learning mechanism. With the structure of benchmark, the damage detection and classification are tested. The simulation results show the classification rate is very well. The algorithm based on the immune learning and evolution can produce the high quality memory cells which effectively identify all kinds of structural damage model.

Abstract: The method of predication is the key for evaluating lifetime remaining of existing bridge in bridge assessment. Improved Gray Model,which can supplement and make full use of new information in time,on the basis of Gray Theory is tried to be used here,and compared with traditional model by analysizing an engineering case.The results show that the improved model can not only improve the precision of prediction,but also comply with the nature of dynamic property of bridge lifetime remaining,i.e.,as the latest inspection information updates the predication value.

Abstract: The elasto-plastic response of the launching site for a missile during the launching phase is studied. Firstly, simulate the asphalt concrete layer with Drucker-Prager/Creep creeping model. Secondly, the finite element model of the launching site is built. Finally, research the elasto-plastic response of launching site under the launch canister under catapult load. The results show that: integral subsidence appears in the unsupported random launching site under catapult load, the sedimentation value of the center point is greater than that in the edge of the launching site under catapult load, the edge of the launching site is higher as a whole than the middle, the stress at the edge of the catapult load is the greatest, the instantaneous stress of the center point under catapult load is the greatest when the launching load finishes.

Abstract: Process quality control is the core in product’s quality management. To solve the problem of multi-causes process quality diagnosis in manufacturing, an algorithm based on binary tree of quality cause set and intermediate quality is proposed. Firstly, the set of quality cause is divided progressively to form a complete binary tree, and then every node of subsets is chose as non-control cause set to construct the cause-selecting control chart of the intermediate qualities in its parent node. In diagnosis, control charts with same parent are compared to narrow the scope of abnormal quality causes until they are confirmed. Practice proves that the proposed algorithm can make the procedure of quality cause judgment independent to the adjustment, thus the comparison times of control charts could be greatly reduced and the efficiency of diagnosis is highly promoted.

Abstract: The reliability of the hydraulic cylinder influences the safe working of the mechanical equipment. So, there are very high technical requirements and machining precision for the hydraulic cylinder. The manufacture deviation of the bore diameter will appear in the machining process. It will influence the working performance of the hydraulic cylinder. The paper determines the influence factors of the hydraulic cylinder machining quality and the different factor level, conducts the orthogonal tests of the boring quality of the hydraulic cylinder. According to the range analysis of all test data, the following conclusions can be drawn. The best match of all kinds of factors is A3B2C2D3. The influence of cutting speed on boring the quality of the hydraulic cylinder is the largest. The influences of cutting tool type, the number of boring tool used in boring, and the feed quantity on the quality of boring are minimum.

Abstract: Recognition of quality abnormal patterns for a dynamic process has seen increasing demands nowadays in the real-time process fault detection and diagnosis. Based on the analysis of the quality abnormal patterns in a dynamic process, a novel method based on multi-feature of quality abnormal patterns by using a multi-SVM (MSVM) was proposed. The simulation results indicate that the recognition accuracies of the MSVM classifiers with the different features are quite different. It is shown that this MSVM model with suitable features can increase the recognition accuracy.

Abstract: This study aims to organically integrate the concept and method of six sigma improvement with the characteristic and experience of aerospace quality improvement, and to develop the conception, main idea, framework of aerospace six sigma improvement suit for the characteristic of aerospace and the method of project identification,improvement and evaluation. Aerospace six sigma improvement is a localization development of six sigma improvement method in aerospace.

Abstract: This paper considers a new H₂/GH₂ sliding mode control in controlling active suspension system subject to mismatched disturbance, without requiring a prior knowledge of disturbance. A quarter-car model is used in the study and the performance of the controller is compared with the existing passive suspension system. A simulation study is presented to prove the effectiveness and robustness of the proposed control method.