期刊文献+
共找到10篇文章
< 1 >
每页显示 20 50 100
基于力限控制技术的点式连接壁挂式发射的卫星振动试验方法
1
作者 崔颖慧 李正举 +2 位作者 裴胜伟 黄华 钱志英 《航天器环境工程》 CSCD 2024年第4期484-488,共5页
对于采用点式连接形式的壁挂式发射卫星,不同星箭接头在发射过程中的加速度谱有较大差异,采用传统方法制定振动试验的加速度控制谱可能导致“过试验”。为此,文章提出一种基于力限控制的振动试验设计方法:通过星箭耦合分析获得星箭界面... 对于采用点式连接形式的壁挂式发射卫星,不同星箭接头在发射过程中的加速度谱有较大差异,采用传统方法制定振动试验的加速度控制谱可能导致“过试验”。为此,文章提出一种基于力限控制的振动试验设计方法:通过星箭耦合分析获得星箭界面处的界面力;振动试验时,在卫星主频处采用力限控制,在其他频段采用加速度谱预先下凹。将该力限控制方法应用于点式连接壁挂式发射卫星振动试验中,试验数据证明了该方法的有效性与可行性。该研究可为后续组批发射卫星地面验证提供参考。 展开更多
关键词 力限控制技术 振动试验 壁挂式发射卫星 加速度控制谱
下载PDF
力限振动试验技术理论基础研究 被引量:2
2
作者 张正平 邱吉宝 +2 位作者 黄波 李海波 任方 《强度与环境》 2011年第4期1-10,共10页
为了深入理解双控方程,由运载火箭有限元模型的多自由度子结构方法,导出缩聚在星/箭连接界面处的全箭动力学方程,定义相应参数后,导出星/箭耦合中的双控方程,给出界面加速度、有源机械系统的自由加速度、界面力、紧固力、源阻抗和负载... 为了深入理解双控方程,由运载火箭有限元模型的多自由度子结构方法,导出缩聚在星/箭连接界面处的全箭动力学方程,定义相应参数后,导出星/箭耦合中的双控方程,给出界面加速度、有源机械系统的自由加速度、界面力、紧固力、源阻抗和负载阻抗表达式,从而加深了对星/箭耦合双控方程的理解,进而促进力限试验技术研究。同时,从多自由度模型简化之后,可以导出力限计算的复杂二自由度模型,并给出源或负载的模态有效质量与剩余质量计算方法。 展开更多
关键词 星/箭耦合分析 力限试验技术 双控方程 子结构方法
下载PDF
力限半经验系数研究 被引量:1
3
作者 马益 秦远田 付国庆 《国外电子测量技术》 2017年第9期86-90,共5页
利用力限技术可以缓解由于星箭界面机械阻抗的差异所造成的过实验现象,半经验法是获取耦合界面力限的重要方法,如何确定半经验系数是关键。基于固定界面子结构模态综合法,推导了半经验系数的理论表达式,分析了半经验常数与星箭耦合系统... 利用力限技术可以缓解由于星箭界面机械阻抗的差异所造成的过实验现象,半经验法是获取耦合界面力限的重要方法,如何确定半经验系数是关键。基于固定界面子结构模态综合法,推导了半经验系数的理论表达式,分析了半经验常数与星箭耦合系统参数之间的关系。基于此方法,以某工程型号卫星为例计算了其半经验系数并制定了正弦实验的力限条件,通过实验数据进行验证,结果表明:该方法所得力限条件能够较好的反映出耦合界面在共振峰处的真实受力。可以为后续力限半经验法的工程应用提供一定的参考。 展开更多
关键词 力限技术 半经验法 星箭耦合系统
下载PDF
Analysis of structural response under blast loads using the coupled SPH-FEM approach 被引量:12
4
作者 Jun-xiang XU Xi-la LIU 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2008年第9期1184-1192,共9页
A numerical model using the coupled smoothed panicle hydrodynamics-finite element method (SPH-FEM) approach is presented for analysis of structures under blast loads. The analyses on two numerical cases, one for fre... A numerical model using the coupled smoothed panicle hydrodynamics-finite element method (SPH-FEM) approach is presented for analysis of structures under blast loads. The analyses on two numerical cases, one for free field explosive and the other for structural response under blast loads, are performed to model the whole processes from the propagation of the pressure wave to the response of structures. Based on the simulation, it is concluded that this model can be used for reasonably accurate explosive analysis of structures. The resulting information would be valuable for protecting structures under blast loads. 展开更多
关键词 Smoothed particle hydrodynamics (SPH) Finite element method (FEM) Reinforced concrete structure Explosion
下载PDF
Upper bound solution for supporting pressure acting on shallow tunnel based on modified tangential technique 被引量:16
5
作者 杨小礼 杨子汉 +1 位作者 李永鑫 李术才 《Journal of Central South University》 SCIE EI CAS 2013年第12期3676-3682,共7页
Based on the nonlinear failure criterion and the upper bound theorem, the modified tangential technique method was proposed to derive the expression of supporting pressure acting on shallow tunnel. Instead of the same... Based on the nonlinear failure criterion and the upper bound theorem, the modified tangential technique method was proposed to derive the expression of supporting pressure acting on shallow tunnel. Instead of the same stress state, different normal stresses on element boundaries were used. In order to investigate the influence of different factors on supporting pressures, the failure mechanism was established. The solution of supporting pressure, with different parameters, was obtained by optimization theory. The corresponding failure mechanism and numerical results were presented. In comparison with the results using the single tangential technique method, it is found that the proposed method is effective, and the good agreement shows that the present solution of supporting pressure is reliable. 展开更多
关键词 shallow tunnel upper bound theorem nonlinear failure criterion modified tangential technique
下载PDF
Prevention of rockburst by guide holes based on numerical simulations 被引量:6
6
作者 ZHU Qi-hu LU Wen-bo +2 位作者 SUN Jin-shan LUO Yi CHEN Ming 《Mining Science and Technology》 EI CAS 2009年第3期346-351,共6页
We studied variations in the stress field around guide holes drilled during tunnel excavation to understand the mechanical mechanism by which these holes help prevent rockburst.The study used elasto-plastic analysis o... We studied variations in the stress field around guide holes drilled during tunnel excavation to understand the mechanical mechanism by which these holes help prevent rockburst.The study used elasto-plastic analysis of a circular chamber under non-axisymmetrical loads.The results showed that the unloading of in-situ stresses, and the forming of a secondary stress field, leads to a severe change in the stress field around the guide holes.This causes the formation of an X-shaped area of plastic deformation, which prevents the rockburst.Adopting a sub-model finite element technique, we analyzed the factors that influence the distribution of the plastic area, such as the guide hole distribution and the in-situ stress state.The calculations showed that higher initial stresses result in greater adjustment to the stress field.When the stress concentration is greater the size of the plastic area surrounding the guide hole is larger.A multi-row distribution of the guide holes shaped like a quincunx can increase the interconnectivity of the plastic areas and allow the plastic area to extend from the tunnel wall deep into the surrounding rock.An optimized design was put forward based on the distribution of the plastic area around guide holes and the factors that influence it. 展开更多
关键词 ROCKBURST guide hole shear failure finite element method sub-model
下载PDF
Estimation of active earth pressure based on pseudo-dynamic approach and discretization technique 被引量:2
7
作者 LUO Wen-jun GONG Chen-jie +1 位作者 WANG Huan-yu YANG Xiao-li 《Journal of Central South University》 SCIE EI CAS CSCD 2021年第9期2890-2904,共15页
A method combining the pseudo-dynamic approach and discretization technique is carried out for computing the active earth pressure.Instead of using a presupposed failure mechanism,discretization technique is introduce... A method combining the pseudo-dynamic approach and discretization technique is carried out for computing the active earth pressure.Instead of using a presupposed failure mechanism,discretization technique is introduced to generate the potential failure surface,which is applicable to the case that soil strength parameters have spatial variability.For the purpose of analyzing the effect of earthquake,pseudo-dynamic approach is adopted to introduce the seismic forces,which can take into account the dynamic properties of seismic acceleration.A new type of micro-element is used to calculate the rate of work of external forces and the rate of internal energy dissipation.The analytical expression of seismic active earth pressure coefficient is deduced in the light of upper bound theorem and the corresponding upper bound solutions are obtained through numerical optimization.The method is validated by comparing the results of this paper with those reported in literatures.The parametric analysis is finally presented to further expound the effect of diverse parameters on active earth pressure under non-uniform soil. 展开更多
关键词 pseudo-dynamic approach discretization technique upper-bound analysis INHOMOGENEITY seismic active earth pressure coefficient
下载PDF
Determination of interference fit value on entire roller embedded shapemeter roll 被引量:5
8
作者 吴海淼 刘宏民 +1 位作者 于丙强 杨利坡 《Journal of Central South University》 SCIE EI CAS 2014年第12期4503-4508,共6页
For entire roller embedded shapemeter roll, the relationship between the value of interference fit and the sensor pre-pressure, and the pressure transfer performance of shapemeter roll were analyzed by elasticity theo... For entire roller embedded shapemeter roll, the relationship between the value of interference fit and the sensor pre-pressure, and the pressure transfer performance of shapemeter roll were analyzed by elasticity theory during the cold reversible rolling process. Considering the influence of strip temperature on the interference fit, the distributions of contact pressure of the framework's top surface and the sensor pre-pressure on different values of interference fit were analyzed by the finite element technology. The results show that the contact pressure of the framework's top surface and the sensor pre-pressure increase with the increase of the value of interference fit. When the value of interference fit is between 0.05 mm and 0.09 mm, roll body's inner hole surface, the framework and pressure magnetic sensitive component don't separate from each other, and the sensor works in the linear segment of characteristic curve, so the normal operation of shapemeter roll is guaranteed. 展开更多
关键词 reversible rolling shapemeter roll value of interference fit contact pressure finite element
下载PDF
A Computational Study of Thrust Vectoring Control Using Dual Throat Nozzle 被引量:7
9
作者 Choon Sik Shin Heuy Dong Kim +1 位作者 Toshiaki Setoguchi Shigeru Matsuo 《Journal of Thermal Science》 SCIE EI CAS CSCD 2010年第6期486-490,共5页
Dual throat nozzle (DTN) is fast becoming a popular technique for thrust vectoring. The DTN is designed with two throats, an upstream minimum and a downstream minimum at the nozzle exit, with a cavity in between the u... Dual throat nozzle (DTN) is fast becoming a popular technique for thrust vectoring. The DTN is designed with two throats, an upstream minimum and a downstream minimum at the nozzle exit, with a cavity in between the upstream throat and exit. In the present study, a computational work has been carried out to analyze the performance of a dual throat nozzle at various mass flow rates of secondary flow and nozzle pressure ratios (NPR). Two-dimensional, steady, compressible Navier-Stokes equations were solved using a fully implicit finite volume scheme. The present computational results were validated with available experimental data. Based on the present results, the control effectiveness of thrust-vectoring is discussed in terms of the thrust coefficient and the coefficient of discharge. 展开更多
关键词 Compressible Flow Dual Throat Nozzle Thrust Vector Control Shock Wave Supersonic Flow
原文传递
Strong Analog Classical Simulation of Coherent Quantum Dynamics
10
作者 Dong-Sheng Wang 《Communications in Theoretical Physics》 SCIE CAS CSCD 2017年第2期171-181,共11页
A strong analog classical simulation of general quantum evolution is proposed, which serves as a novel scheme in quantum computation and simulation. The scheme employs the approach of geometric quantum mechanics and q... A strong analog classical simulation of general quantum evolution is proposed, which serves as a novel scheme in quantum computation and simulation. The scheme employs the approach of geometric quantum mechanics and quantum informational technique of quantum tomography, which applies broadly to cases of mixed states, nonunitary evolution, and infinite dimensional systems. The simulation provides an intriguing classical picture to probe quantum phenomena, namely, a coherent quantum dynamics can be viewed as a globally constrained classical Hamiltonian dynamics of a collection of coupled particles or strings. Efficiency analysis reveals a fundamental difference between the locality in real space and locality in Hilbert space, the latter enables efficient strong analog classical simulations. Examples are also studied to highlight the differences and gaps among various simulation methods. 展开更多
关键词 quantum simulation geometric quantum mechanics phase space
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部