Advanced Materials Research Vols. 472-475

Abstract: With the improvement of people's living standard, the building energy consumption is increasing day by day. In order to reduce energy consumption, we should develop energy-saving building and analyze building energy saving technology. This article mainly introduces three kinds of energy saving technology which include the external wall thermal insulation technology, doors and Windows energy saving technology and roof insulation technology.

Abstract: This article proposes a framework of in-situ monitoring for anomaly detection of avionics, Uses the multi-variant Hotelling T2 statistics to form a quickly reference to the anomaly behavior. The proposed method can be used to solve the data driven Prognostics and Health Management problem to detect the anomaly behavior of equipment as well as the potential isolation and diagnosis of the symptoms of incoming faults. The article also gives a structure of an on-line test and monitoring system prototype, based on the legacy on-line test system, as well as developed a basic information gathering route and a multi-variant test based anomaly detection method. A fault injection based simulation experiment was formed to validate the performance of the system and method under consideration. The results shows that the proposed method has a solid mathematics fundamental and the advantages as well as good performance, worth to be spread.

Abstract: Springback is the most common defect in sheet metal forming. The compensation method is an effective way to overcome this defect by modifying the die-face. A new geometrical springback compensation algorithm based on UV curves is proposed for automobile structure die-face. The UV discrete technology and space lattice search approach are adopted to get the regular springback lattices from irregular and unordered springback points. The compensation direction and the correction of the pressing direction are considered. The die-face is reconstructed with a high order BEZIER spline surface on the CATIA platform. The high quality geometry compensation die-face obtained from this algorithm can be applied directly in actual machining. The geometry springback compensation of a high strength steel structure part is used to verify the effectiveness of the algorithm.

Abstract: Automated guided vehicle (AGV) is a kind of wheeled mobile robot, which used for the internal and external transport of materials from one place to another in flexible manufacture system (FMS). AGV are also used for repeating transportation tasks in other areas, such as warehouses, container terminals and external (underground) transportation systems. The AGV navigation algorithms are classified as global or local, depending on surrounding environment. In global navigation, the environment surrounding the AGV is known and the path which avoids the obstacle is selected. In local navigation, the environment surrounding the AGV is unknown, and sensors are used to detect the obstacles and avoid collision. In the past, a number of algorithms have been designed by many researchers for robot navigation problems. Through analyzing the existing positioning methods and precision for AGV, this paper design and develop a new navigation software based on multi-sensor information fusion algorithm, it is proved through the theory analysis and experiment that the position precision of AGV is ≤±5mm, posture precision is ≤±0.3°. It can full meet the requirements of robot’s accuracy.

Abstract: Based on research on the knitting processes, an impact mechanic model for knitting elements was established to investigate the variation of the impact force in vertical direction between the cam and the select jack. The variation of the displacement, velocity, acceleration of the select jack and the stability for the needles’ moving has been confirmed by the simulation of knitting process based on the software ANSYS/LS-DYNA. Furthermore, the variation of the select jack has been confirmed by experimental measurement during the knitting process. The data of the experiment results were in accordance with the ANSYS’ simulation which verified the correctness of the ANSYS’ analysis. It provided a theoretic basis for the design of computerized flat knitting machines.

Abstract: Transient temperature fields of directional solidification of Al-Ni-Co alloys were studied by employing finite element method. Temperature gradient at solidification front and solidification rate was analyzed under different pouring temperature of molten steel. The results show that with different initial pouring temperatures of molten steel, individual ratio of temperature gradient at solidification front to solidification rate soars up in the initial stage of solidification, then varies within 2000-6000°C•s•cm-2, and finally plunges down and goes together when the solidification thickness reaches 5-6cm. Simulation result is consistent with the production reality. Numerical simulation results can provide an available reference for process optimization of directional solidification of Al-Ni-Co alloys.

Abstract: A theoretical analysis for the effect mechanism of elliptic vibration assistance on the cutting of brittle materials is presented in this paper. The crack propagation in the chip formation zone in cutting of brittle materials is examined based on an analysis of the geometry and forces in the cutting region. The cutting model shows that the actual undeformed chip thickness is much decreased with elliptic vibration assistance, and the instantaneous rake angle of the cutting tool edge is also in a larger negative value than those in conventional cutting. These two conditions can ensure the compressive stress is much larger than the shear stress during the cutting process. Then the stress intensify factor is suppressed effectively and the shielding effect on the growth of pre-existing flaws is strengthened in the chip formation zone. The removal of brittle material tends to be in ductile mode without fracture. The characteristic examination of cutting force shows that the ratio of thrust force to cutting force with elliptic vibration is increased compared to that of conventional cutting. This can validate that the larger compressive stress can be generated in the chip formation zone with elliptic vibration assistance. The transition depth to brittle machining of silicon carbide with/without elliptic vibration assistance further supports the presented theory.

Abstract: According to the necessity for researching the optimization of enterprise energy-consuming based on model, the identification method for energy-consuming link in enterprise production process was researched. In view of the existing problems of Least Squares Support Vector Machine (LS-SVM), a modeling method based on Liu-transformation and LS-SVM was proposed. Liu-transformation was applied to intelligent data analysis for extracting typical characteristics from the training samples, and then the data were trained to construct the energy-consuming model based on on-line LS-SVM algorithm. The simulation result showed that the presented modeling method has the advantages of shorter computing time, robust and better generalization ability.

Abstract: The true stress-strain curve of aluminum alloy 6005A is attained by quasi-static compression experiments, and Johnson Cook material model parameters of aluminum alloy 6005A is determined by using least-squares fitting. The aluminum alloy 6005A finite element model of the oblique cutting process is established in ABAQUS software, and verified by the oblique cutting simulation and experiments. The finite element model of high-speed side milling process is also established and the influence of milling cutter spiral angle on cutting force is analyzed.

Abstract: In this paper, industrial diamonds using FeNi powder catalyst with additive La2O3 has been synthesized by HPHT method. Optical microscope, XRD and SEM were utilized for observation and detection. The influences of additive La2O3 on the synthesis have been investigated from several aspects such as the diamond-forming conditions, the composition of synthesized sample and inclusions in diamond, and the morphology character of diamonds etc. The results indicate that There is a new compound LaO, LaFeO3, Fe3C and Fe3O4 in the sample., and related phenomena were given in detail in this paper.