摘要：推进速度是全断面岩石隧道掘进机(Tunnel boring machine,TBM)的重要设计参数。其值过小将降低机械的掘进效率;过大将引起刀盘的大幅振动,导致联接螺栓超常松动、引起主轴承塑性变形与断裂,严重影响施工安全。为确定推进速度的临界值,引入非线性弹簧单元模拟破岩过程中滚刀与岩石的相互作用,采用有限元法对刀盘掘进过程进行动态仿真,得到了在不同岩层中掘进时保证刀盘动力稳定性的推进速度临界值。所得结果可为合理设计TBM推进速度,有效控制刀盘振动,减少振动破坏,提升TBM的地质适应性和施工安全性提供参考。

摘要：Micro/nano-thin films are widely used in the fields of micro/nano-electromechanical system(MEMS/NEMS)and flexible electronics,and their mechanical properties have an important impact on the stability and reliability of ***,accurate characterization of the mechanical properties of thin films still faces challenges due to the complexity of film-substrate structure,and the characterization efficiency of traditional techniques is *** this paper,a high-throughput determination method of the elastic modulus of thin films is proposed based on the strain variance method,the feasibility of which is analyzed by the finite element method(FEM),and the specific tensile configuration with array-distributed thin films is designed and *** on the strain difference between the film-substrate region and the uncoated region,the elastic modulus of multiple films is obtained simultaneously,and the influences of film width,spacing,thickness,and distribution on the measurement of elastic modulus are *** results show that the change in film width has a more obvious effect on the elastic modulus determination than film spacing and thickness,i.e.,the larger the film width is,the closer the calculation results are to the theoretical value,and the change in calculation results tends to be stabilized when the film width increases to a certain ***,the simultaneous measurement of the elastic modulus of eight metal films on a polyimide(PI)substrate with a length of 110 mm and a width of 30 mm can be realized,and the testing throughput can be further increased with the extension of the substrate *** study provides an efficient and low-cost method for measuring the elastic modulus of thin films,which is expected to accelerate the development of new thin film materials.

摘要：针对挖泥船绞刀挖岩过程中绞刀切削力难以预测的问题,本文应用有限元方法建立了模拟绞刀挖岩过程的三维分析模型。采用罚刚度的接触约束算法确定绞刀与岩体的接触状态和接触作用力,利用扩展的DruckerPrager塑性模型以及包含单元删除功能的损伤演化模型模拟岩体变形及破碎,从而获得了绞刀挖岩过程中绞刀的切削力,并进行了实验验证。结果表明:绞刀转速恒定时,切削载荷和功率均随绞刀横移速度增大而显著增大;绞刀横移速度恒定时,功率随转速增大而增大,但切削载荷却有所下降;适当降低绞刀转速和提高横移速度有利于降低岩石切削比能。这些结果可为新型挖泥船绞刀设计提供参考。

摘要：Cutterhead loads are the key mechanical parameters for the strength design of the full face hard rock tunnel boring machine(TBM).Due to the brittle rock-breaking mechanism,the excavation loads acting on cutters fluctuate strongly and show some *** conventional method that using combinations of some special static loads to perform the strength design of TBM cutterhead may lead to strength failure during working *** this paper,a three-dimensional finite element model for coupled Cutterhead–Rock is developed to determine the cutterhead *** the distribution characteristics and the influence factors of cutterhead loads are analyzed based on the numerical *** is found that,as time changes,the normal and tangential forces acting on cutters and the total torque acting on the cutterhead approximately distribute log normally,while the total thrusts acting on the cutterhead approximately show a normal ***,the statistical average values of cutterhead loads are proportional to the uniaxial compressive strength(UCS)of cutting *** values also change with the penetration and the diameter of cutterhead following a power *** on these findings,we propose a three-parameter model for the mean of cutterhead loads and a method of generating the random cutter *** the strength properties of a typical cutterhead are analyzed in detail using loads generated by the new *** optimized cutterhead has been successfully applied in *** method in this paper may provide a useful reference for the strength design of TBM cutterhead.

摘要：介绍了道路轴载谱快速实测系统组成及工作流程,分析了道路轴载谱快速实测技术的影响因素,并通过对实际道路轴载大数据的深入挖掘,分析了检测时间点和时间段(检测持续时间)对数据代表性的影响。结合山东省某重载交通省级干线公路,阐述了道路轴载谱快速实测技术的实际应用,对该道路路面结构进行了分析,提出了相应的设计建议。