科创中国

选用碳纤维(CF)、玻璃纤维(GF)和高强玻璃纤维(SGF)为增强材料,制作CF,CF/GF和CF/SGF层间组合混杂纤维增强木梁,并对其受弯性能进行了试验研究,同时分析了该木梁的破坏形态和破坏机理,讨论了其荷载-位移特征、极限承载力和延性.结果表明:与单一CF增强相比,合理匹配混杂纤维增强复合材料(HFRP)可显著提高木梁的承载力和延性.提出了HFRP增强木梁的极限承载力计算方法.

Fiber reinforced polymer (FRP) composite materials having advantages such as higher strength to weight than conventional engineering materials, non-corrosiveness and modularization, which should help engineers to obtain more efficient and cost effective structural materials and systems. Currently, FRP composites are becoming more popular in civil engineering applications. The objectives of this research are to study performance and behavior of light weight multi-cellular FRP composite bridge decks (both module and system levels) under various loading conditions through finite element modeling, and to validate analytical response of FRP composite bridge decks with data from laboratory evaluations. The relative deflection, equivalent flexural rigidity, failure load (mode) and load distribution factors (LDF) based on FE results have been compared with experimental data and discussed in detail. The finite element results showing good correlations with experimental data are presented in this work.

The strain distributions near the interface when the elbow steel fiber is pulled out from the half-mould concrete matrix are directly measured using a combined method of single fiber pull-out test and digital image correlation. Meanwhile, the real-time processes of the bonding, debonding and sliding at the interface are observed. The micro-mechanism of the strain localization in the failure process of interface when debonding occurs and the strengthening mechanism at the imbedded fiber are discussed. The experimental results show that the meso-scale strain localization gives rise to the localization of shear damage near the fiber interface. This strain localization characterized by the debonding process near the interface occurs, develops and moves gradually at an apparently regular interval. At the elbow part of the imbedded fiber, the peak value of the shearing stress occurs. But the primary debonding does not occur at this place because the strength of the shear damage is increased at the local area of the elbow part in the concrete, displaying an apparent reinforced effect at the end of the fiber.

对外径为Ф10mm碳纤维复合材料管成型工艺及性能进行了研究.结果表明,采用热缩工艺成型的碳纤维复合材料管工艺简单、质量可靠,Ф10mm碳纤维复合材料管件弯曲刚度与不锈钢管相当,弯曲强度为不锈钢的3倍以上,质量仅为不锈钢的50%,尺寸精度满足设计要求.

Layered organic-inorganic hybrids containing bilayer perovsikte (R-NH3)2(CH3NH3)Pb2I7 (where R=C12H25,C6H5C2H4) were synthesized by reactions in solution. The influences of the solvents and the reactant ratio on the structures of the products were investigated. The structures and the properties of the hybrids were characterized using X-ray diffraction (XRD) and ultraviolet and visible (UV) adsorption spectra. For comparing with the bilayer perovskite hybrids in structure and band gap magnitude, the hybrids containing monolayer perovskite (R-NH3)2PbI4 were also synthesized and characterized. The results demonstrate that the thickness of inorganic layer has obvious effect on the tunneling magnitude of the band gap but the organic part can be micro actuator of band gap.

Though the studies of wheel-legged robots have achieved great success, the existing ones still have defects in load distribution, structure stability and carrying capacity. For overcoming these shortcomings, a new kind of wheel-legged robot(Rolling-Wolf) is designed. It is actuated by means of ball screws and sliders, and each leg forms two stable triangle structures at any moment, which is simple but has high structure stability. The positional posture model and statics model are built and used to analyze the kinematic and mechanical properties of Rolling-Wolf. Based on these two models, important indexes for evaluating its motion performance are analyzed. According to the models and indexes, all of the structure parameters which influence the motion performance of Rolling-Wolf are optimized by the method of Archive-based Micro Genetic Algorithm(AMGA) by using Isight and Matlab software. Compared to the initial values, the maximum rotation angle of the thigh is improved by 4.17%, the maximum lifting height of the wheel is improved by 65.53%, and the maximum driving forces of the thigh and calf are decreased by 25.5% and 12.58%, respectively. The conspicuous optimization results indicate that Rolling-Wolf is much more excellent. The novel wheel-leg structure of Rolling-Wolf is efficient in promoting the load distribution, structure stability and carrying capacity of wheel-legged robot and the proposed optimization method provides a new approach for structure optimization.

Now the optimization strategies for power distribution are researched widely,and most of them are aiming to the optimal fuel economy and the driving cycle must be preknown.Thus if the actual driving condition deviates from the scheduled driving cycle,the effect of optimal results will be declined greatly.Therefore,the instantaneous optimization strategy carried out on-line is studied in this paper.The power split path and the transmission efficiency are analyzed based on a special power-split scheme and the efficiency models of the power transmitting components are established.The synthetical efficiency optimization model is established for enhancing the transmission efficiency and the fuel economy.The identification of the synthetical efficiency as the optimization objective and the constrain group are discussed emphatically.The optimization is calculated by the adaptive simulated annealing(ASA)algorithm and realized on-line by the radial basis function(RBF)-based similar models.The optimization for power distribution of the hybrid vehicle in an actual driving condition is carried out and the road test results are presented.The test results indicate that the synthetical efficiency optimization method can enhance the transmission efficiency and the fuel economy of the power-split hybrid electric vehicle(HEV)observably.Compared to the rules-based strategy the optimization strategy is optimal and achieves the approximate global optimization solution for the power distribution.The synthetical efficiency optimization solved by ASA algorithm can give attentions to both optimization quality and calculation efficiency,thus it has good application foreground for the power distribution of power-split HEV.

综述了聚合物脱挥设备的分类和基本情况,并着重介绍了双螺杆挤出机在聚合物脱挥领域中的应用、优点、国内外发展概况及发展趋势等,同时在大量工业化应用的基础上提出了切实可行的同向双螺杆挤出机脱挥工艺,并详细分析了同向双螺杆挤出机主要零部件的设计要求和设计方法.

通过试验研究了聚丙烯(PP)纤维和植物纤维素(UFPP)纤维对受荷混凝土渗透性能的影响.结果表明:在一定荷载范围内,纤维混凝土的抗渗能力有所提高,当荷载超过混凝土破坏荷载30%左右时,其抗渗能力随之下降.同时研究了纤维对各龄期混凝土抗氯离子渗透性能及抗冻融循环耐久性能的影响,并分析了其机理.

采用带有PVT口模的流变仪测定无定型聚合物熔体在压力0~50 MPa,温度453~563 K时的PVT(压力-体积-温度)特性曲线,分别用基团贡献修正胞腔模型(GCMCM)和胞腔模型对实测的PVT数据进行预测.结果表明:在实验中用基团贡献修正胞腔模型的比容平均预测误差较胞腔模型要大得多,其预测精度要略差于胞腔模型,这说明基团贡献修正胞腔模型的应用具有一定的局限性.同时还计算出了2种模型所对应的特征值,并分析了其特征值存在的共同点和差异的原因.