Applied Mechanics and Materials Vols. 26-28

Abstract: In this paper, the poplar LVL was reinforced with monolayer fiberglass mesh. The reinforcing effect of monolayer fiberglass mesh on improving the static bending strength (or modulus of rupture, MOR) was studied. And three different nondestructive testing (NDT) methods, such as the longitudinal transmission method, longitudinal vibration method and flexural vibration method (out-plane and in-plane), were used to test the dynamic Young’s modulus of the reinforced poplar LVL. The linear relationships were investigated between the four dynamic Young’s moduli and the MOR of the reinforced poplar LVL. It can be concluded that the three NDT methods are useful for predicting the MOR of reinforced LVL, but the flexural and longitudinal vibration methods had better accuracy to estimate the MOR.

Abstract: Effects of glue spread, adhesive kind and curing agent ratio and FRP (Fiber Reinforced Plastic) on stiffness of wood-FRP bonding interface were investigated. Two different kinds of epoxy resin and one kind of curing agent were used to bond wood-wood and wood-FRP samples with three different glue spread. Shear modulus of samples were measured by compression shear test to represent the stiffness of bonding interface. The results indicated that curing agent ratio and glue spread had significant effect on stiffness of wood-wood and wood-FRP bonding interfaces. In addition, the stiffness of wood-FRP interface was less than that of wood-wood interface.

Abstract: Effects of fiber fabric type, glue spread and adhesive kind on stiffness of fiber-wood bonding interface were investigated. Four different kinds of fiber fabric were bonded into poplar sample with three different adhesives and three different glue spread. Shear modulus of samples were measured by compression shear test to represent the stiffness of bonding interface. The results indicated that stiffness of GFF (Glass Fiber Fabric)-wood and GFMa (Glass Fiber Mat)-wood interfaces was better than that of two other interfaces and shear modulus of CFF (Carbon Fiber Fabric)-wood samples were the least of all. And the effects of glue spread and adhesive kind on stiffness of fiber-wood interface were significant.

Abstract: Network Security Situation Awareness (NSSA) helps security analysts to be aware of the actual security situation of their networks. But its adaptive control model and method remain a new research field that needs to be explored. In this paper, we presented a novel NSSA adaptive control model based on cognitive network. The model adopted circle cognitive structure composed of Monitor, Awareness, Decision and Execution (MADE). In the MADE cognitive circle, we described a fusion awareness method based on PSO-DS theory. The decision and execution strategies were also discussed briefly. The experiments prove that our model realizes the adaptive regulation of NSSA effectively and it also can be applied into other fields in order to develop automatic tools and devices.

Abstract: In most practical engineering optimal problems, the sensitivities of quality characteristics is affected by the deviation of design variables, and the evaluation of quality is multi-aspect. In web press’s fold mechanism design, the trace deviation and entrance angle in working state are important criterions which affect the folding knife’s kinematic performance. In order to improve the synthetic kinematics performance, a multiple objective robust optimum design model could be established, based on the analysis of sensitive response to the design variables and determining proper evaluation strategies. By comparing the results of multiple objective robust optimum design and common optimum design, we can find that the synthetic kinematics performance of multiple objective robust optimum design is much better.

Abstract: In response to the problems of automobile oil consumption direct test and indirect test, Ultrasonic technology and microcontroller control technology can be used to research automobile oil consumption testing technique. Deciding on the method of automobile oil consumption testing is based on the fluid testing principle of ultranonic wave technology and build a mathematical model of automobile oil consumption tesing, According to the functional requirements of oil consumption, design the automobile oil consumption system hardware, control circuit and control automation programming to achieve the oil consumption inteligence non-disintegrated measuring. By means of tests and data processing analaysis and modifying the theoretical model, the theory used by the system is feasible and oil consumption measuring system with low power consumption and high accuracy.

Abstract: A saddle curve is formed by intersection of two tubes. The trajectory control of saddle curve is usually carried out through approximating the curve as segments of straight line/circular arc for CNC interpolation. Based on the principle of space analytic geometry, this paper proposes a new trajectory control approach to directly interpolate the saddle curve for automated welding/cutting system. Simulation of the direct interpolation algorithm of saddle curve has been carried out to verify the effectiveness of the proposed algorithm. It also demonstrates that the interpolation error is well within the accuracy requirements and the proposed algorithm is potentially useful for the cutting/welding of saddle curve of tubular joints.

Abstract: A new composite, wood-polymer composite, was fabricated by formation of poly (methyl methacrylate) in wood cellular structure. Methyl methacrylate (MMA) monomer and a few of 2,2'- azobisisobutyronitrile (AIBN) as an initiator, as well as several drops of pyrimidine as catalyst were first impregnated into wood porous structure under a pressure condition, and then initiated for thermal polymerization through a catalyst-thermal treatment. The structure of Wood-PMMA Composite was characterized by SEM, FTIR, XRD, and its thermal stability was also examined. The results indicate that PMMA polymer generated in wood cellular structure as an amorphous form, and interacted with wood cell walls, resulting in chemical combination between them. The thermal stability of Wood-PMMA composite was higher than untreated wood under 450°C.

Abstract: The cutter’s position and pose are key elements for chamfering addendum automatically and a new method for calculating the cutter’s position and pose is as follows: 1) Finding the chamfering boundary curves of addendum by offsetting the two top curves (convex and concave) of spiral bevel gear addendum respectively; 2) Dispersing the chamfering boundary curves; 3) Calculating the center position of the tangent circle along the chamfering boundary curves and taking this as the cutter’s center; 4) solving the tilt angle through the center position and the dispersed points on boundary curves. The proposed method lays foundation for chamfering automation.

Abstract: The universal NC program was inefficient for machining centrifugal pump vanes and a new tool-path generation method along section lines was proposed in this paper. After analyzing curve characteristics of centrifugal pump vanes, the mathematical model for calculating cutting step-lengths and determining the next tool contact parameter ui+1 through step estimating method was put forward. Furthermore, a new iterative algorithm was implemented, along with its terminal condition simplified. The proposed algorithm provided a new idea for developing special NC program of impellers.