摘要：A study was conducted to analyze the deformation mechanism of strongly weathered quartz schist in the Daliangshan Tunnel,located in the western Transverse Mountain area.A large deformation problem was experienced during the tunnel *** mitigate this problem,a support system was designed incorporating negative Poisson ratio(NPR)anchor cables with negative Poisson ratio *** model experiments,field experiments,and numerical simulation experiments were conducted to investigate the compensation mechanical behavior of NPR anchor *** large deformations of soft rocks in the Daliangshan Tunnel are caused by a high ground stress,a high degree of joint fracture development,and a high degree of surrounding rock fragmentation.A compensation mechanics support system combining long and short NPR anchor cables was suggested to provide sufficient counter-support force(approximately 350 kN)for the surrounding rock inside the *** the NPR anchor cable support system with the original support system used in the Daliangshan tunnel showed that an NPR anchor cable support system,combining cables of 6.3 m and 10.3 m in length,effectively prevented convergence of surrounding rock deformation,and the integrated settlement convergence value remained below 300 *** study provides an effective scientific basis for resolving large deformation problems in deeply buried soft rocks in western transverse mountain areas.

摘要：昆虫和微型飞行器存在间隙狭窄的串列式拍动翼-固定翼构型.与独立的拍动翼相比,两翼之间的干扰作用可以增强推力,但推力增量能否通过倾斜拍动平面而转化为升力尚不清楚.本文采用浸润边界法和格子玻尔兹曼方法研究了这种串列双翼构型在不同拍动平面倾角下的气动性能。结果表明,当拍动平面倾角为75°时,干扰作用产生的大部分推力增量转化为升力增量,证明了通过倾斜拍动平面实现升推转化的可行性。除了几何投影和有效迎角改变的贡献外,升力增量还来自于两翼位置最接近时的额外升力峰,其流动机制包括两部分:一方面,固定翼阻碍了拍动翼产生的射流并在间隙内产生了较强的水平回流,从而增强了拍动翼上翼面后缘附近的低压区;另一方面,固定翼前方的上洗气流增强了拍动翼下翼面的高压区.进一步分析表明,这种增升机制在多个拍动幅度下有效,因此可以认为该机制在三维构型中仍然存在。上述研究结果揭示了一种通过倾斜拍动平面来增强串列式拍动翼-固定翼构型升力的新机制,为以这种构型为基础的微型飞行器提供了新设计方案.

摘要：本文介绍了一种深基坑大型止水屏障(部分重叠的高压旋喷桩组成)的分析方法,该方法考虑了其两个关键的因素(渗透性与材料强度)。随后,通过对一个算例进行了分析和讨论。结果表明,在基坑止水屏障参数设计时应主要考虑其拉裂破坏模式,其中最大允许渗流量是重要的设计指标之一,其对确定基坑止水屏障设计参数具有十分显著的影响。与本文提出的设计方法相比,由于忽略止水屏障结构自身渗透性能和材料强度对结构安全的贡献,采用稳定平衡法或渗流稳定平衡法进行确定基坑止水屏障设计参数是相对保守的。在此基础上,以福州地铁某深基坑工程为例,采用本文提出的设计方法,确定了深基坑止水屏障厚度与深度的范围值。最后,现场抽水试验结果表明现场基坑止水屏障的水密性能十分良好。

摘要：The hoist bracket links the rescue hoist with the helicopter cabin, and its structure design greatly affects the operation convenience and safety of the hoistman and lifeguard in the rescue process with a *** paper firstly builds the force model of the hoist and bracket, and gives five kinds of typical working conditions as the design ones of the bracket. Then this paper puts forward a design process of the hoist bracket based on the topology optimization and strength analysis with the 3D modeling and finite element analysis. This design process can make the bracket's structure lightweight by achieving the optimal material layout under the conditions of maximizing the static stiffness or minimizing the compliance of the bracket. And this improves the dynamic performance of the helicopter, and reduces the fuel consumption and cost under the strength constraints. Finally,taking the design of the hoist bracket used in a rescue helicopter as an example, this paper illustrates the proposed model and method. The analysis results show that the mass of the hoist bracket decreases by 12.5% while the static stiffness of the hoist bracket is achieved. The optimization design results meet the strength requirements of the hoist.

摘要：Wave transmission and overtopping around nearshore breakwaters can have significant influence on the transmitted wave parameters,which affects wave conditions and sediment transportation and becomes the focus of design in *** objective of this paper is to present a simplified model to estimate these important wave *** paper describes the incorporation of wave transmission and overtopping module into a wave model for multi-directional random wave transformation based on energy balance equation with the consideration of wave shoaling,refraction,diffraction,reflection and ***'s frequency spectrum and non-linear dispersion relation are also included in this *** influence of wave parameters of transmitted waves through a smooth submerged breakwater has been considered in this model with an improved description of the transmitted wave spectrum of van der Meer et al.(2000) by Carevic et al.(2013).This improved wave model has been validated through available laboratory *** the verified model is applied to investigate the effect of wave transmission and overtopping on wave heights behind low-crested breakwaters in a project for nearshore *** calculations are carried out with and without consideration of the wave transmission and overtopping,and comparison of them indicates that there is a considerable difference in wave height and thus it is important to include wave transmission and overtopping in modelling nearshore wave field with the presence of low-crested ***,this model can provide a general estimate of the desired wave field parameters,which is adequate for engineers at the preliminary design stage of low-crested breakwaters.

摘要：To improve design capabilities for the knitted fabric pattern,a preliminary study is carried out for the design *** on mathematical theory,pattern could be created automatically by computer with inputting different parameters for mathematical *** knitted fabric simulation is realized by M1 CAD pattern preparation system of STOLL *** the pattern,different color unit is replaced by obverse stitch with different color,or by obverse stitch and reverse stitch with the same color separately,after that the effects of knitted fabrics could be *** with this method,it would not only help to acquire a great of diversity patterns,but also improve design efficiency and save cost.

摘要：In order to achieve an access to strain sensor data with wireless transmission in bridge engineering structure testing, a wireless strain test system is presented based on the resistance strain sensor of networks. The wireless bridge strain test system composed of master station and substation adopts the wireless method to realize the high accuracy data acquisition between the master station and the substation under a reliable communication protocol. The system has been tested in contrast with the present strain apparatus. Results show that the wireless system is high-reliable, and has many characteristics such as high efficiency, good precision, high stability with low cost, and good flexibility, without using the present communication network.

摘要：基于流场恶化理论和声学类比理论建立了一套声学优化设计方法,并应用于高速列车排障器的声学优化设计中。结果表明,头尾车流线体是最重要的声源,分别占总声能的23.7%和33.7%。与尾车流线型部位相比,头车流线型部位声源能量更偏向高频。车体A计权辐射噪声呈现宽频带噪声(主要在1~4 kHz范围内)和峰值特征(尤其在2 kHz)。在四种方案中,最大伸缩长度的排障器能缓和2 k Hz的强峰值效应,降低总声能,并表现出最佳的声辐射性能。通过风洞试验验证了数值计算模型的正确性。

摘要：Crimping is widely adopted in the production of large-diameter submerged-arc welding pipes. Traditionally, designers obtain the technical parameters for crimping from experience or by trial and error through experiments and the finite element(FE) method. However, it is difficult to achieve ideal crimping quality by these approaches. To resolve this issue, crimping parameter design was investigated by multi-objective optimization. Crimping was simulated using the FE code ABAQUS and the FE model was validated experimentally. A welding pipe made of X80 high-strength pipeline steel was considered as a target object and the optimization problem for its crimping was formulated as a mathematical model and crimping was optimized. A response surface method based on the radial basis function was used to construct a surrogate model; the genetic algorithm NSGA-II was adopted to search for Pareto solutions; grey relational analysis was used to determine the most satisfactory solution from the Pareto solutions. The obtained optimal design of parameters shows good agreement with the initial design and remarkably improves the crimping quality. Thus, the results provide an effective approach for improving crimping quality and reducing design times.

摘要：受最新材料科学、计算机技术、人工智能和自动控制技术的启发,新一代交通基础设施正在走向数字化和智能化。世界上许多主要发达国家都在因地制宜,积极推动智能创新技术在交通基础设施中的应用。本文首先简要介绍了交通基础设施智能化的基本概念、科学依据和发展历程。然后,按照设计、施工、运维、淘汰的全生命周期链条,系统分析了智能化技术的研究现状和面临的主要挑战。随后,以世界上第一条基于智能建设理念建设的铁路——北京-张家口高铁为例,全面介绍了智能技术的最新成就。最后,从标准体系、理论方法和人才培养三个维度对交通基础设施智能化的未来发展进行了探讨。