摘要：To strengthen Specific Energy-Absorption(SEA)behavior of Sandwich Composite Structure(SCS),a kind of light-weight vertical stiffener is proposed for the corrugated *** vertical stiffener,embedded in the corrugated core,can not only absorb part of energy but also simultaneously enhance Energy-Absorption(EA)of other *** Hashin damage model considering the shear stress and ductile damage model is adopted to predict the failure of carbon fiber face-sheets and aluminum-core,*** perfect bonding is modeled for interfaces between the face-sheet and core due to little realistic *** finite element model is verified by available data of conventional *** obtain more design ideas,several stiffeners with different thicknesses,numbers,and positions are *** the predicted results,both the flexural load and deformation of SCS correlate well with experimental *** is highlighted that the SCSs with different vertical stiffeners exhibit 9.74%-58.48%higher SEA than the SCS without *** complex reinforcement mechanisms are extensively revealed by underlying coupling EA and deformation *** parameter analysis shows that the thickness and number have significant effects on the flexural behavior and SEA of reinforced SCS.

摘要：Soft rock surrounding deep roadway has poor stability and long-term rheological effect. More and larger deformation problems of surrounding rock occur due to adverse supporting measures for such roadways, which not only affects the engineering safety critically but also improves the maintenance costs. This paper takes the main rail roadway with severely deformation in China＇s Zaoquan coal mine as an example to study the long-term deformation tendency and damage zone by means of in-situ deformation monitoring and acoustic wave testing technique. A three-dimensional finite element model reflecting the engineering geological condition and initial design scheme is established by ABAQUS. Then, on the basis of field monitoring deformation data, the surrounding rock geotechnical and theological parameters of the roadway are obtained by back analysis. A combined supporting technology with U-shaped steel support and anchor-grouting is proposed for the surrounding soft rock. The numerical simulation of the combined supporting technology and in-situ deformation monitoring results show that the soft rock surrounding the roadway has been held effectively.

摘要：根据Lagrange方程建立了单级倒立摆系统的数学模型,利用模糊自适应控制算法设计了倒立摆系统的控制器,并在Matlab的仿真模块中将倒立摆系统的数学模型和控制器结合起来,对倒立摆控制系统进行了仿真研究。结果表明,对于要求实时性较高的非线性不稳定系统,用模糊自适应控制算法可以按照控制要求在线调节控制参数,在最短的调整时间内取得良好的控制效果。

摘要：Seashells,commonly referred to as nature’s armors against predatory attacks,have been serving as the inspirations for designing strong and tough engineering *** studies on conch shells have been focused on the shell body *** conch spines which are evenly distributed at the tail of conch shell are generally accepted as the decoration,enabling conch shells as art *** we report a new finding that nature uses curved reinforcements,different from the straight ones in conch body parts,to construct conch spines which exhibit 30%increase in fracture strength compared to conch shell body *** curved lamellae not only endow conch spines with pyramid-shape but also add extra shielding to the *** equilibrium state,the curved lamellar configuration withholds 3 times higher loading than the straight *** finding uncovered nature’s wisdom in constructing seashells and provides an additional design guideline for utilizing curved reinforcements to achieve multifunctionalities and superior mechanical prowess.

摘要：Inner-reinforced girders, also known as ribs, are widely used in hydropower bifurcations. However, while they strengthen structures, they also cause energy loss. This work aims to develop an appropriate geometry form for ribs that can diminish head loss in hydropower bifurcations. The term rib/breadth ratio (RBR) is defined to describe the geometrical form of ribs. An investigation is conducted to study the flow and performance characteristics of bifurcations with ribs using computational fluid dynamics. The dependence of the head loss coefficient on the RBR is given in six working conditions. Results show that the ribs change the local flow patterns and slightly increase the water head loss in some cases. In other cases, however, the ribs make the flow smooth. An appropriate RBR is the key to improve the flow patterns in hydropower bifurcations. The head loss varies with the RBR and reaches the minimum when the RBR is 0.3. © 2017, Tianjin University and Springer-Verlag GmbH Germany.