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排序方式: 共有132条查询结果,搜索用时 31 毫秒
61.
旋喷桩止水帷幕在北京站扩能改造工程基坑支护中的应用 总被引:1,自引:0,他引:1
介绍旋喷桩的施工原理以及在北京站扩能改造工程中的应用 相似文献
62.
The asymmetric deformation and eccentricity problems of near hemispherical diaphragm under the uniform surface load are quantitatively
characterized in the paper. The analysis is based on a 3D finite element analysis (FEA) model established according to elastic-plasticity
and large displacement nonlinear finite element method. Besides, the deformation experiments are taken to validate the reliability
of FEA model which shows that the simulation results are in good agreement with the experimental results. Then, three angle
parameters, deflection angle β, circumvolving angle θ and distributing angle γ, are introduced and expressed to characterize the asymmetric deformation and eccentricity quantitatively. According to the
angle parameters, the inversion processes of uniform thickness diaphragm and varying thickness diaphragm are calculated respectively.
The inversion process of varying thickness diaphragm is much steadier than that of uniform thickness diaphragm. The present
results show that the asymmetric deformation process can be characterized by curve of three angle parameters (β, θ, γ) exactly, the degrees of eccentricity can be indicated by the final value of deflection angle and the eccentricity position
can be characterized by the final values of the three angle parameters. 相似文献
63.
The performance of vacuum arc remelting (VAR) ingot depends largely on ingot structure and chemical uniformity, which are
strongly influenced by molten pool profile that is influenced by VAR process. To better understand the effect of remelting
current on molten pool profile of titanium alloy ingot during VAR process, a 3D finite element model is developed by the ANSYS
software. The results show that there are three remelting stages during VAR process when the remelting current is 2.0 kA.
The molten pool depth increases gradually from 30 to 320 s, then the change of molten pool depth is very small during the
steady state stage from 320 to 386 s, and lastly the molten pool depth becomes shallow after 386 s. The melting rate and temperature
of superheat increase with the remelting current increasing, which leads to the augment of molten pool volume. In the end,
the total remelting time and steady state molten pool time decrease with the melting current from 1.6 to 2.8 kA. 相似文献
64.
In this paper, the effects of hardening exponent, yield strength and elastic modulus on the deformability of near hemispherical
shells are investigated by means of finite element method and orthogonal experiment design. The largest eccentric angle during
the deformation process and thickness reduction after the deformation are introduced to estimate the deformability quantitatively
according to the deformation characteristics of near hemispherical shells. The results indicate that the hardening exponent
is the most influential parameter, followed by elastic modulus and yield strength. The shell exhibits good deformability when
the hardening exponent and elastic modulus are in the range of 0.1–0.125 and 70–108 GPa, respectively. 相似文献
65.
66.
采用移动Agent技术构建了一种新的电子拍卖系统模型.讨论了系统的协商协议、协商策略、应价策略和移动Agent的关键技术.给出了移动Agent的迁移实现实例。 相似文献
67.
68.
如何确定责任分摊和计算补偿数额是处理提前终止PPP项目的核心议题.为使PPP项目提前终止补偿计算有据可依,提高提前终止处置效率和科学性,通过文献和案例研究,结合专家调查结果,从提前终止主体责任、责任主体管理水平、提前终止收益、项目实施社会影响4个维度识别11个PPP项目提前终止责任分摊影响因素.运用三角模糊层次分析法确... 相似文献
69.
超车工况下高速客车操纵稳定性仿真与试验研究 总被引:1,自引:1,他引:0
在分析大客车结构和载荷分布的基础上,根据乘员人体工程学和系统动力学原理,建立了九自由度客车模型。对客车模型的仿真结果和实车试验结果进行了对比,验证了该模型的正确性和实用性。同时,利用此模型仿真分析了悬架参数变化对高速超车工况客车操纵稳定性的影响。 相似文献
70.
汽车可控悬架系统的研究进展 总被引:7,自引:0,他引:7
总结了汽车可控悬架的发展状况,详细阐述了半主动悬架、主动悬架等的结构形式及国内外最新研究成果,提出了新型可能量再生的可切换的主动/半主动悬架结构方案,并进行了台架试验。评价了用于可控悬架的主要控制策略,指出应着重研究非线性控制与智能控制方法的综合运用,研究和开发可能量回收的汽车智能悬架,重点包含制动、转向、可控悬架的底盘集成控制。 相似文献