鹤壁五矿深部软岩交岔点研究与应用

随着煤矿采深的不断加大,深部软岩交岔点稳定性控制已成为煤矿开采的又一难题。为了良好地控制交叉点处围岩的稳定性问题,结合鹤壁五矿三水平二车场交岔点处支护工程实例,通过地质调查、理论分析及数值模拟(FLAC3D),提出了鹤壁五矿三水平二车场交岔点处围岩稳定性控制对策——锚网喷+锚索+单桁架耦合支护技术,并在实践中得到了验证,效果良好。     

联轴节压装工艺改进

文章针对某项目动车组电机侧联轴节滞缓现象,介绍联轴节基本结构和压装工艺,从联轴节锥度、压装方式、扩张液等多方面分析联轴节压装的影响因素,并优化改进联轴节及其压装工艺。     

Physical–biological coupling in spore dispersal of kelp forest macroalgae

The physical–biological linkages controlling the dispersal of spores produced by macroalgae that reside in kelp forests are complicated and laced with feedbacks. Here we discuss the fundamental elements of these interactions. Biological considerations include spore swimming and sinking speeds, their periods of viability in the plankton, and the height of spore release above the seafloor, which together determine the durations over which spores can be swept by horizontal currents before they contact the seafloor. Morphologies and material properties of canopy forming kelps may also influence the drag exerted on passing waters by the kelps, the plants' ability to persist in the face of rapid flows, and thereby the degree to which impinging currents are redirected around, or slowed within, kelp forests. Macroalgal life histories, and the size of spore sources as controlled by the dimensions of kelp forests and the density and fecundity of individuals within them, influence effective dispersal distances as well. Physical considerations encompass the mean speed, direction, and timescales of variability of currents relative to spore suspension times, the interaction of surface gravity waves with currents in producing turbulence in the benthic boundary layer, wind-driven surface mixing, water stratification, and shoreline bathymetry and substratum roughness, all of which can affect the interplay of vertical and horizontal transport of macroalgal spores. Intricate within-forest processes may induce attenuation of current speeds and consequent reductions in seabed shear, along with simultaneous production of small-scale turbulence in kelp wakes. Slower mean currents and smaller eddy scales in turn may attenuate vertical mixing within forests, thus extending spore suspension times. Further complexities likely arise due to changes in the relative rates of horizontal and vertical dispersion, modifications to the overall profiles of vertical mixing, and the creation of fine-scale secondary flows around kelp individuals and substratum features. Under conditions of more rapid currents, submergence of the surface canopy and the establishment of skimming flows at the canopy–fluid interface may introduce additional coherent flow structures that alter rates of fluid exchange to and from the forest. Many of these coupled physical–biological processes are just beginning to be examined in a rigorous fashion in kelp forests, but their potential importance is clear.     

客运专线曲线线路车线耦合系统动力学性能与无砟轨道结构振动响应的仿真研究

依据系统工程理论的思想,对客运专线曲线线路车线耦合系统的动力学性能和无砟轨道结构车辆线路耦合系统振动响应问题进行分析和仿真研究,主要研究内容如下。(1)基于车辆—轨道耦合动力学理论和有限元理论,系统分析车线耦合系统中各部分的运动状态,分别建立机车车辆、普通曲线线     

船用柴油机润滑油配伍试验研究

本文首先介绍了柴油机主要摩擦副——缸套和活塞环的磨损机理,然后提出了对曲柄箱润滑油的要求,其中最主要的是润滑油自始至终必须保持一定的碱性。作者还阐述了合理选择气缸润滑油的依据和方法,最后在我所的试验机上选用3种(A、B、C)不同配伍的润滑油作抗磨性,清净分散性比较试验,得出A优于B,B优于C,及A、B、C3种都可正常使用的结论。     

船载货物单元在非规则波中系固有效性校核的一种评价方法

货物单元在运输中,合理系固是确保船舶安全的重要因素,而系固方案制定后,如何针对实际海况对其系固效果进行正确评价则是货物系固的关键.在非规则波的基础上,充分考虑到各自由度运动之间的耦合影响,提出一种更为贴近海上实际的系固有效性校核的评价方法,同时将风力、波溅力、摩擦力等因素考虑到此方法当中,由此得出的结论会更客观.也为完善系固方案提供了依据,并可作为《货物积载和系固安全操作规则(CSS Code)》的补充.     

变工况下船舶艉轴机械密封端面温度场数值分析

以变工况下的船舶艉轴机械密封环为研究对象,采用整体接触耦合法对其进行了热力耦合作用下的温度场有限元计算,重点介绍了船舶艉轴密封环稳态温度场数学计算模型和热流密度载荷的施加思路,依据接触表面的温度连续性条件对变工况时密封端面的接触状况及温度变化趋势进行了分析.结果表明:转速、海水压力以及载荷系数都是引起端面温升的重要原因,各工况下静、动环接触区温度相同,非接触区静环端面温度高于动环,且在热力耦合作用下,密封端面发生锥形变形,呈现开口间隙.     

裂隙围岩的双场耦合可靠性分析

应力场和渗流场在裂隙围岩中的耦合变化规律,是非常复杂的力学过程。运用断裂损伤力学和可靠性评价原理,可推导出裂隙围岩可靠度表达式,说明可靠度与应力分布、渗流力作用、节理分布和岩体性质的相互关系。文章利用推导的裂隙围岩可靠度表达式,在雪峰山隧道YK97 847处进行计算验证,结果表明,在裂隙围岩中,可靠度低的部位不一定在主应力方位,也不一定在隧道顶端,而是因地应力分布、渗透水压、节理分布和岩体性质等综合作用,使局部围岩可靠度相对较低,该处围岩最容易变形坍塌。此研究结果可为隧道支护施工提供参考。     

对旧路加宽存在问题的研究

随着我国经济的迅速发展,一些现有公路已不能适应交通量增长的要求,需要扩大道路通行能力,面临改扩建问题,而新老路基结合处就成为路基施工的重点。结合大齐公路改建工程,分析了旧路路基施工时可能产生问题,提出合适的施工方案。通过研究找出有效避免施工过程中新旧旧路基结合部产生问题的原因,制定解决方案保证路基稳定性。研究成果对公路改建工程新旧路结合部的设计与施工具有借鉴意义。     

高速机车制动温升对轴盘配合的影响

利用ANSYS建立了高速机车轴盘制动装置热量传递模型,计算了接触面热阻、间隙导热系数和表面传热系数,研究了其温度场分布特性,分析了制动生热对轴盘制动装置过盈配合的影响。计算结果表明:合理的制动盘和盘毂间隙能增大热阻,减小温度对过盈配合的影响,在结构允许范围内,建议合理的设计单边间隙为0.5~1.5mm;制动结束时刻,选择合理的盘毂厚度可使过盈面平均接触压力减小5.9%~6.6%,以降低温度对过盈配合的影响,建议盘毂合理厚度为8mm。