Applied Mechanics and Materials Vols. 16-19

Abstract: Configurable MES is a hot attention in today’s industry. In this work, we present a MES model based on a production process modeling method. With the workflow management technology, a configurable MES framework is introduced and some important implementation methods such as production process modeler, activity script language and production process scheduler are presented. A successful application of an automobile engine assembly line shows that this model is useful and effective.

Abstract: In this paper, a hybrid method of correlation analysis based on the gray theory and the least squares support vector machine is proposed to model the thermal error of spindle of NC machine tool and predict the thermal error. The gray correlation analysis is used to optimize the measuring points of spindle. The optimum measuring points and the measured thermal error of spindle are regarded as the data to be trained to build the thermal error prediction model based on the least squares support vector machine (LS-SVM). The results show that the thermal error prediction model based on LS-SVM of NC machine tool has advantages of high precision and good generalization performance. The prediction model can be used in real-time compensation of NC machine tool and can prove the process precision and reduce cost.

Abstract: This paper presents recent developments in the study of optimization methods for industrial product design, and provides a method of dynamic optimization design to calculate the optimal loading property of automobile twist bar spring system. This is a different approach to traditional systems that is based on dynamic and random load, applying the basic theory and methods of dynamic design, according to the multi-goal characteristic of automobile twist bar spring. This paper presents a thorough analysis dynamic quadratic fuzzy optimal method of double-goal and the method to determine paper optimal gene. This method is used to automobile twist bar spring design, the result shows that the ability of spring loading is improved; the weight of structure is reduced. The new approach makes the vibration absorbing system more reliable and comfortable. The results presented in this paper are not only applicable to automobile twist bar spring systems but all systems that possess dynamic, random and fuzzy characteristics. This work finds applications in automobile components design and dynamic character analysis.

Abstract: A method of feature line extraction from triangular mesh model is presented. Firstly, initial feature point is manually specified based on feature points extraction from triangular mesh model. Then begin with initial feature point, Principal Component Analysis (PCA) method is applied to analyze primary direction of special feature region of feature points. Search the feature point which is furthest from the center of mass in the primary direction and it is chosen as subsequent feature point. Iteratively, record the feature point sequence in order. Finally, use three order non-uniform B-spline curve to fit and construct feature line. The experimental results demonstrate that the proposed method in this paper is efficient.

Abstract: For product development projects, to void the risk of project delay, all the tasks should be finished as soon as possible. However, the critical chain method (CCM) requires the non-critical tasks to be executed as late as possible. In this paper, the traditional CCM is revised based on the characteristics of product development. Other than the traditional one, the revised CCM is created based on the active plan, that is, all tasks should be executed as early as possible. And then, the schedule scheme of active plan based critical chain method is given, including searching critical chain, no-critical chain and setting buffers. Consulting in the resource constrained project scheduling problem (RCPSP), an optimal model of CCM is built.

Abstract: It is the key step to construct the fuzzy complementary judgment matrix and rank the weighting of the judgment matrix when we apply the fuzzy analytic hierarchy process (FAHP). In this paper, a method of rank the weighting which is based on the idea of additive consistent fuzzy complementary judgment matrix and Euclidean space distance, namely the Euclidean space distance weighting ranking method (EDWM) is recommended. In the end of this paper, a case is given to verify the feasibility and accuracy of this method.

Abstract: Business process flexibility (BPF) is critical for enterprises in improving their competition abilities. In this paper, the business process flexible degree is introduced firstly. Then, the BPF is divided into three tiers, and each flexible degree is described. At last, an optimization model for business process flexibility is built for a process design.

Abstract: The cold extrusion forming of copper/aluminum clad composite based on the low pressure casting billet is presented in this paper. The technology was studied by using the experimental investigation and the finite element method. The drop-in phenomenon occurred in aluminum during the extrusion forming process. The product will be having good quality when the extrusion ratio is 5.45 and the extrusion modular angle is 30°. The crack appeared on the head of product when the extrusion ratio and extrusion angle is large than the aforementioned values.

Abstract: From the view of the point of the systems engineering, the model of 7D planning of product design is presented in this paper based on the previous work. The planning of products design includes design ideas, design environments, design objective, design process, design contents, design methods and the design quality evaluation methods, so named 7D planning model. Besides the understanding of the customer requirements, the seven aspects of 7D planning should be considered completely and planned systematically. The paper makes a detailed expatiation of the 7D planning model of synthesized design method based on systems engineering.

Abstract: Based on the modeling and experiments concerning the surface roughness in abrasive jet finishing with grinding wheel as restraint, the effect of abrasive size, abrasive fluid concentration, machining cycle, wheel velocity and carrier fluid on machined surface quality was investigated. Surface grinder M7120 was employed in a jet machining experiment conducted with W18Cr4V and 40Cr materials, profilometer TALYSURF was used to measure the micro geometrical parameters after machining, and SEM was used to observe surface micro-morphology. Experimental results show that with W7 Al2O3 powder at the mass fraction of 10% and antirust lubricating liquid being adopted in jet machining for 20 to 30 cycles, not only high surface shape precision can be kept or obtained, but also defect-free machined surface with the roughness of Ra0.15～1.6µm can be obtained with high efficiency. Experimental observation and experimental results proved that the experimental results agree well with a mechanism-based machining model.