期刊文献+
共找到3,856篇文章
< 1 2 193 >
每页显示 20 50 100
Theoretical and numerical simulation investigation of deep hole dispersed charge cut blasting
1
作者 Chengxiao Li Renshu Yang +3 位作者 Yanbing Wang Yiqiang Kang Yuantong Zhang Pin Xie 《International Journal of Coal Science & Technology》 EI CAS CSCD 2023年第1期87-107,共21页
Drilling and blasting methods have been used as a common driving technique for shallow-hole driving and blasting in rock roadways.With the advent of digital electronic detonators and the need for increased production ... Drilling and blasting methods have been used as a common driving technique for shallow-hole driving and blasting in rock roadways.With the advent of digital electronic detonators and the need for increased production efciency,the traditional blasting design is no longer suitable for deep hole blasting.In this paper,a disperse charge cut blasting method was proposed to address the issues of low excavation depth and high block rate in deep hole undercut blasting.First,a blasting model was used to illustrate the mechanism of the deep hole dispersive charge cut blasting process.Then,continuous charge and dispersed charge blasting models were developed using the smooth particle hydrodynamics-fnite element method(SPHFEM).The cutting parameters were determined theoretically,and the cutting efciency was introduced to evaluate the cutting efect.The blasting efects of the two charging models were analyzed utilizing the evolution law of rock damage,the number of rock particles thrown,and the cutting efciency.The results show that using a dispersed charge improves the cutting efciency by about 20%and the rock breakage for the deep hole cut blasting compared to the traditional continuous charge.In addition,important parameters such as cutting hole spacing,cutting hole depth and upper charge proportion also have a signifcant impact on the cutting efect.Finally,the deep hole dispersed charge cut blasting technology is combined with the digital electronic detonator through the feld engineering practice.It provides a reference for the subsequent deep hole cutting blasting and the use of electronic detonators in rock roadways. 展开更多
关键词 deep hole blasting Cut blasting Dispersed charge SPH-FEM Digital electronic detonator
下载PDF
Construction and Weight Distributions of Binary Linear Codes Based on Deep Holes
2
作者 Yong Yang Wenwei Qiu 《Applied Mathematics》 2023年第10期684-695,共12页
Deep holes are very important in the decoding of generalized RS codes, and deep holes of RS codes have been widely studied, but there are few works on constructing general linear codes based on deep holes. Therefore, ... Deep holes are very important in the decoding of generalized RS codes, and deep holes of RS codes have been widely studied, but there are few works on constructing general linear codes based on deep holes. Therefore, we consider constructing binary linear codes by combining deep holes with binary BCH codes. In this article, we consider the 2-error-correcting binary primitive BCH codes and the extended codes to construct new binary linear codes by combining them with deep holes, respectively. Furthermore, three classes of binary linear codes are constructed, and then we determine the parameters and the weight distributions of these new binary linear codes. 展开更多
关键词 Linear Codes MacWilliams Equations Weight Distribution Dual Codes deep holes Covering Radius
下载PDF
Stability and nonlinear dynamic behavior of drilling shaft system in copper stave deep hole drilling 被引量:2
3
作者 孔令飞 李言 +3 位作者 吕延军 李德信 李淑娟 汤奥斐 《Journal of Central South University》 SCIE EI CAS 2009年第3期451-457,共7页
The stability and nonlinear dynamic behavior of drilling shaft system in copper stave deep hole drilling were analyzed. The effects of the fluctuation of the cutting force, the mass eccentricity and the hydrodynamic f... The stability and nonlinear dynamic behavior of drilling shaft system in copper stave deep hole drilling were analyzed. The effects of the fluctuation of the cutting force, the mass eccentricity and the hydrodynamic forces of cutting fluid could be taken into consideration in the model of drilling shaft system. Based on the isoparametric finite element method, the variational form of Reynolds equation in hydrodynamic fluid was used to calculate nonlinear hydrodynamic forces and their Jacobian matrices simultaneously. In the stability analysis, a new shooting method for rapidly determining the periodic orbit of the nonlinear drilling shaft system and its period was presented by rebuilding the traditional shooting method and changing the time scale. Through the combination of theories with experiment, the correctness and effectiveness of the above methods are verified by using the Floquet theory. The results show that the mass eccentricity can inhibit the whirling motion of drilling shaft to some extent. 展开更多
关键词 copper stave deep hole drilling drilling shaft NONLINEARITY BIFURCATION
下载PDF
Theory and application of rock burst prevention using deep hole high pressure hydraulic fracturing 被引量:3
4
作者 Shan-Kun ZHAO Jun LIU +3 位作者 Xiang-Zhi WEI Chuan-Hong DING Yu-Lei LV Gang-Feng LI 《Journal of Coal Science & Engineering(China)》 2013年第2期136-142,共7页
In order to analyze the mechanism of deep hole high pressure hydraulic fracturing, nonlinear dynamic theory, damage mechanics, elastic-plastic mechanics are used, and the law of crack propagation and stress transfer u... In order to analyze the mechanism of deep hole high pressure hydraulic fracturing, nonlinear dynamic theory, damage mechanics, elastic-plastic mechanics are used, and the law of crack propagation and stress transfer under two deep hole hydraulic fracturing in tectonic stress areas is studied using seepage-stress coupling models with RFPA simulation software. In addition, the effects of rock burst control are tested using multiple methods, either in the stress field or in the energy field. The research findings show that with two deep holes hydraulic fracturing in tectonic stress areas, the direction of the main crack propagation under shear-tensile stress is parallel to the greatest principal stress direction. High-pressure hydraulic fracturing water seepage can result in the destruction of the coal structure, while also weakening the physical and mechanical properties of coal and rock. Therefore the impact of high stress concentration in hazardous areas will level off, which has an effect on rock burst prevention and control in the region. 展开更多
关键词 rock burst deep hole high pressure hydraulic fracturing seepage-stress coupling models stress concentration factor
下载PDF
Picosecond Laser Machining of Deep Holes in Silicon Infiltrated Silicon Carbide Ceramics 被引量:1
5
作者 张青 WANG Chunhui +2 位作者 LIU Yongsheng ZHANG Litong CHENG Guanghua 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2015年第3期437-441,共5页
Silicon infiltrated silicon carbide (Si-SiC) ceramics, as high hardness materials, are difficult to machine, especially drilling micro-holes. In this study, the interaction of picosecond laser pulses (1 ps at 1 030... Silicon infiltrated silicon carbide (Si-SiC) ceramics, as high hardness materials, are difficult to machine, especially drilling micro-holes. In this study, the interaction of picosecond laser pulses (1 ps at 1 030 nm) with Si-SiC ceramics was investigated. Variations of the diameter and depth of circular holes with the growth of the laser energy density were obtained. The results indicate that the increase of machining depth follows a nonlinear relation with the increasing of laser energy density, while the diameter has little change with that. Moreover, it is found that some debris and particles are deposited around and inside the holes and waviness is in the entrance and at walls of the holes after laser processing. 展开更多
关键词 picosecond laser deep holes silicon infiltrated silicon carbide ceramic
原文传递
On Deep Holes of Projective Reed-Solomon Codes over Finite Fields with Even Characteristic
6
作者 XU Xiaofan 《Wuhan University Journal of Natural Sciences》 CAS CSCD 2023年第1期15-19,共5页
Projective Reed-Solomon code is an important class of maximal distance separable codes in reliable communication and deep holes play important roles in its decoding.In this paper,we obtain two classes of deep holes of... Projective Reed-Solomon code is an important class of maximal distance separable codes in reliable communication and deep holes play important roles in its decoding.In this paper,we obtain two classes of deep holes of projective Reed-Solomon codes over finite fields with even characteristic.That is,let F_(q) be finite field with even characteristic,k∈{2,q-2},and let u(x)be the Lagrange interpolation polynomial of the first q components of the received vector u∈F_(q)+1 q Suppose that the(q+1)-th component of u is 0,and u(x)=λx^(k)+f_(≤k-2)(x),λx^(q-2)+f_(≤k-2)(x),where λ∈F^(*)_(q) and f_(≤k-2)(x)is a polynomial over F_(q) with degree no more than k-2.Then the received vector u is a deep hole of projective Reed-Solomon codes PRS(F_(q),k).In fact,our result partially solved an open problem on deep holes of projective Reed-Solomon codes proposed by Wan in 2020. 展开更多
关键词 finite field even characteristic projective Reed-Solomon code deep hole
原文传递
On deep holes of standard Reed-Solomon codes 被引量:10
7
作者 WU RongJun HONG ShaoFang 《Science China Mathematics》 SCIE 2012年第12期2447-2455,共9页
Determining deep holes is an important open problem in decoding Reed-Solomon codes. It is well known that the received word is trivially a deep hole if the degree of its Lagrange interpolation polynomial equals the di... Determining deep holes is an important open problem in decoding Reed-Solomon codes. It is well known that the received word is trivially a deep hole if the degree of its Lagrange interpolation polynomial equals the dimension of the Reed-Solomon code. For the standard Reed-Solomon codes [p-1, k]p with p a prime, Cheng and Murray conjectured in 2007 that there is no other deep holes except the trivial ones. In this paper, we show that this conjecture is not true. In fact, we find a new class of deep holes for standard Reed-Solomon codes [q-1, k]q with q a power of the prime p. Let q≥4 and 2≤k≤q-2. We show that the received word u is a deep hole if its Lagrange interpolation polynomial is the sum of monomial of degree q-2 and a polynomial of degree at most k-1. So there are at least 2(q-1)qk deep holes if k q-3. 展开更多
关键词 deep hole Reed-Solomon code cyclic code BCH code DFT IDFT
原文传递
Experimental and computational analysis of the coolant distribution considering the viscosity of the cutting fluid during machining with helical deep hole drills 被引量:1
8
作者 Ekrem Oezkaya Sebastian Michel Dirk Biermann 《Advances in Manufacturing》 SCIE EI CAS CSCD 2022年第2期235-249,共15页
An experimental analysis regarding the distribution of the cutting fluid is very difficult due to the inaccessibility of the contact zone within the bore hole.Therefore,suitable simulation models are necessary to eval... An experimental analysis regarding the distribution of the cutting fluid is very difficult due to the inaccessibility of the contact zone within the bore hole.Therefore,suitable simulation models are necessary to evaluate new tool designs and optimize drilling processes.In this paper the coolant distribution during helical deep hole drilling is analyzed with high-speed microscopy.Micro particles are added to the cutting fluid circuit bya developed high-pressure mixing vessel.After the evaluation of suitable particle size,particle concentration and coolant pressure,a computational fluid dynamics(CFD)simulation is validated with the experimental results.The comparison shows a very good model quality with a marginal difference for the flow velocity of 1.57%between simulation and experiment.The simulation considers the kinematic viscosity of the fluid.The results show that the fluid velocity in the chip flutes is low compared to the fluid velocity at the exit of the coolant channels of the tool and drops even further between theguidechamfers.Theflow velocity and the flow pressure directly at the cutting edge decrease to such an extent that the fluid cannot generate a sufficient cooling or lubrication.With the CFD simulation a deeper understanding of the behavior and interactions of the cutting fluid is achieved.Based on these results further research activities to improve the coolant supply can be carried out with great potential to evaluate new tool geometries and optimize the machining process. 展开更多
关键词 Computational fluid dynamics(CFD)analysis:Viscosity-Tracermicro particles Fluidbehavior Helical deep hole drilling
原文传递
Finite Geometry and Deep Holes of Reed-Solomon Codes over Finite Local Rings
9
作者 Jun Zhang Haiyan Zhou 《Communications in Mathematical Research》 CSCD 2022年第2期206-222,共17页
In this paper, we first propose the maximum arc problem, normal rational curve conjecture, and extensions of normal rational curves over finite local rings, analogously to the finite geometry over finite fields. We th... In this paper, we first propose the maximum arc problem, normal rational curve conjecture, and extensions of normal rational curves over finite local rings, analogously to the finite geometry over finite fields. We then study the deep hole problem of generalized Reed-Solomon (RS) codes over finite local rings. Several different classes of deep holes are constructed. The relationship between finite geometry and deep holes of RS codes over finite local rings are also studied. 展开更多
关键词 Finite geometry finite local ring Reed-Solomon code covering radius deep hole
原文传递
Characteristics of helical flow in slim holes and calculation of hydraulics for ultra-deep wells 被引量:1
10
作者 Fu Jianhong Yang Yun +1 位作者 Chen Ping Zhao Jinhai 《Petroleum Science》 SCIE CAS CSCD 2010年第2期226-231,共6页
Due to the slim hole at the lower part of the ultra-deep and deep wells, the eccentricity and rotation of drill string and drilling fluid properties have great effects on the annular pressure drop. This leads to the f... Due to the slim hole at the lower part of the ultra-deep and deep wells, the eccentricity and rotation of drill string and drilling fluid properties have great effects on the annular pressure drop. This leads to the fact that conventional computational models for predicting circulating pressure drop are inapplicable to hydraulics design of deep wells. With the adoption of helical flow theory and H-B rheological model, a computational model of velocity and pressure drop of non-Newtonian fluid flow in the eccentric annulus was established for the cases where the drill string rotates. The effects of eccentricity, rotation of the drill string and the dimensions of annulus on pressure drop in the annulus were analyzed. Drilling hydraulics was given for an ultra-deep well. The results show that the annular pressure drop decreases with an increase in eccentricity and rotary speed, and increases with a decrease in annular flow area. There is a great difference between static mud density and equivalent circulating density during deep well drilling. 展开更多
关键词 Ultra-deep well slim hole annular velocity annular pressure drop hydraulics
下载PDF
Mechanism and practice of rock control in deep large span cut holes 被引量:2
11
作者 Li Chong Xu Jinhai +2 位作者 Fu Chunsheng Wu Rui Ma Qianqian 《Mining Science and Technology》 EI CAS 2011年第6期891-896,共6页
Deep large span cut holes are difficult to stabilize. The 7801 cut hole in the Lu'an Wuyang Mine was used as this project's background. The main factors affecting large span cut hole stability are analyzed. Pr... Deep large span cut holes are difficult to stabilize. The 7801 cut hole in the Lu'an Wuyang Mine was used as this project's background. The main factors affecting large span cut hole stability are analyzed. Pre- stressed bolting theory was used to design a roof control method for a large span roadway. By reducing the span and applying equal strength coordinated supports the rock could be stabilized. The control prin- ciples and methods are given herein along with the analysis. A double micro arch cross section roadway is defined and its use in solving the current problem is described. Beam arch theory was used to build a model of the double micro arch cross section roadway. A support reverse force model for the arch foot intersection was also derived. A support method based upon reducing the width of the large span in the cut hole is presented. These results show that the reduced span of the roadway roof plus the use of cable anchors and single supports gives an effective way to control the large span cut hole. On site monitoring showed that the reduced span support from the double micro arch cross section roadway design had a significant effect. The roadway surface displacement was small and harmful deformation of the cut hole was effectively controlled. This will ensure its long term stability. 展开更多
关键词 deep large span cut hole Double micro arch cross-section roadway Roof control by cross cut Equal strength coordinated support
下载PDF
中凯矿业大直径深孔爆破落矿装药结构优化研究 被引量:1
12
作者 赵兴东 宋景仪 +1 位作者 田斌 范晓苏 《爆破》 CSCD 北大核心 2024年第1期60-66,共7页
装药结构对厚大矿体大直径深孔爆破落矿效果具有重要影响。中凯矿业帮中矿区现行装药结构(空气间隔长度比例24.2%)存在爆破后冲破坏作用严重的问题,造成后一排炮孔堵塞、坍塌甚至报废,严重影响生产效率;而盲目增大空气间隔长度比例则存... 装药结构对厚大矿体大直径深孔爆破落矿效果具有重要影响。中凯矿业帮中矿区现行装药结构(空气间隔长度比例24.2%)存在爆破后冲破坏作用严重的问题,造成后一排炮孔堵塞、坍塌甚至报废,严重影响生产效率;而盲目增大空气间隔长度比例则存在爆破大块率增加的风险。以矿山实际的炸药和岩石参数为基础,采用数值模拟软件LSDYNA开展大直径深孔爆破落矿装药结构优化研究。选择常用空气间隔器作为间隔材料,以空气间隔长度比例为研究对象设计了12种装药结构方案进行数值模拟,得到了装药结构与爆破后冲作用、大块率、自由面质点振动峰值速度以及峰值有效应力等评价指标之间的关系。结果表明:自由面质点振动峰值速度以及峰值有效应力随空气间隔长度比例增加逐渐下降;当空气间隔长度比例小于等于30.5%时后冲作用明显,后排炮孔可能出现塌孔现象,当空气间隔长度比例大于等于45.3%时,存在大块率增加的风险,最优装药结构的空气间隔长度比例为44.2%。现场深孔爆破落矿试验表明,优化的装药结构爆破后大块率为7.1%且爆破后冲作用得到有效控制。 展开更多
关键词 大直径深孔爆破落矿 装药结构 数值模拟 大块率
下载PDF
Heptad Phase Vortex Array in Extremely Deep Fresnel Diffraction Region Generated by Asymmetrical Metal Subwavelength Holes Film
13
作者 姜淑娜 李杏 +3 位作者 马力 高雅茹 桂维玲 程传福 《Chinese Physics Letters》 SCIE CAS CSCD 2015年第10期63-67,共5页
We report a heptad vortex array structure in the wave fields in an extremely deep Fresnel diffraction region by asymmetrical subwavelength holes in a metal film illuminated with linearly polarized light. A Mach Zehnde... We report a heptad vortex array structure in the wave fields in an extremely deep Fresnel diffraction region by asymmetrical subwavelength holes in a metal film illuminated with linearly polarized light. A Mach Zehnder interferometer with a microscopic objective is used to record the wave fields at different distance& and the phase maps are extracted by Fourier transform of the interference intensities. We study the evolutions of the heptad vortex array with distance from the sample to the object plane. To explain the formations and the evolutions of the vortex array, we calculate the diffracted wave fields with Kirchhoff's diffraction theory. The calculations are basically consistent with the experimental results, and the properties of the heptad vortex array structure are reasonably explained. 展开更多
关键词 Heptad Phase Vortex Array in Extremely deep Fresnel Diffraction Region Generated by Asymmetrical Metal Subwavelength holes Film
原文传递
BTA深孔加工镗杆的横向随机振动
14
作者 赵武 张全斌 +1 位作者 李亚敏 荆双喜 《振动与冲击》 EI CSCD 北大核心 2024年第3期46-57,共12页
采用随机方法分析了蕴含轴向流动流体的BTA(boring and trepanning association)深孔镗杆在随机力下的横向随机动力行为。建模时考察了流固耦合镗杆承受的弯曲、拉伸和扭转变形;经Galerkin Method离散化处理,分析了BTA镗杆在有、无随机... 采用随机方法分析了蕴含轴向流动流体的BTA(boring and trepanning association)深孔镗杆在随机力下的横向随机动力行为。建模时考察了流固耦合镗杆承受的弯曲、拉伸和扭转变形;经Galerkin Method离散化处理,分析了BTA镗杆在有、无随机激励两种情况的特征值和特征频率对振动特性的影响;利用响应方差最大值和谱密度解析了BTA镗杆横向振动的临界转速与临界失稳频率;明确了镗杆随转速、刚度、初始轴向总力和剪切模量等参数变化对系统振动特性的影响机制:镗杆转速变化对系统稳定性不再具有单调性,随BTA镗杆转速持续增加,系统可历经两次转速的临界失稳,相继出现二次失稳和二次稳定;增加系统等效刚度和等效剪切模量会促进工作过程的稳定,改变轴向力对工作过程稳定的影响不明显;并以随机振动物理试验信号的功率谱分析,验证了理论仿真结果与试验结果的一致性。该研究在一定程度上揭示了BTA深孔工艺系统运动状态的复杂性,这种研究模式为进一步分析在复杂状态下的运动演化提供了更多的可能。研究结论为更好地理解BTA深孔镗杆工作时的随机动力行为提供了依据,也为BTA深孔工艺过程的振动控制和参数优化奠定了理论基础。 展开更多
关键词 BTA深孔镗杆 横向振动 随机振动特性 特征值 响应方差 谱密度
下载PDF
综采面坚硬顶板超深孔预裂爆破远场解危控制技术
15
作者 徐颖 杨敬轩 +3 位作者 傅菊根 黄文尧 杨荣周 王梦想 《工程爆破》 CSCD 北大核心 2024年第5期112-124,共13页
工程实践表明,顶板事故在煤矿各类事故中占首要位置,已严重制约了我国现代化矿井安全高效开采。为了实现煤矿综采面坚硬顶板的安全治理,亟需形成综采面坚硬顶板超深孔预裂爆破远场解危控制技术以有效解决因工作面大空间坚硬顶板垮落而... 工程实践表明,顶板事故在煤矿各类事故中占首要位置,已严重制约了我国现代化矿井安全高效开采。为了实现煤矿综采面坚硬顶板的安全治理,亟需形成综采面坚硬顶板超深孔预裂爆破远场解危控制技术以有效解决因工作面大空间坚硬顶板垮落而影响安全生产的重大难题。基于此,通过自主创新和联合攻关,面向深部矿井坚硬顶板,开展了综采面坚硬顶板超深孔预裂爆破远场解危技术研究;研发了高威力三级煤矿许用水胶炸药、填塞材料等技术与装备,形成了成熟的深孔爆破工艺,突破了厚硬顶板爆破中煤矿许用炸药威力与安全度的矛盾,解决了超深孔爆破中炸药可靠起爆等技术瓶颈问题;通过构建大空间采场覆岩-支架-围岩系统力学模型,揭示了采场大小周期来压及强矿压作用机理,提出了大空间采场厚硬覆岩多层位精准定位爆破弱化控制原理和基于爆破损伤的综采工作面厚硬顶板深孔爆破参数设计方法,形成了综采工作面厚硬顶板超前深孔卸压控制技术。研究成果在全国近百个综采面进行工程应用,未发生一起顶板事故,避免了综采面厚硬顶板发生压架、形成飓风、矿震等重大安全事故的风险,保障了综采面的安全高效生产,为综采面坚硬顶板远场解危的设计提供了理论依据并为现场施工提供了指导作用。 展开更多
关键词 综采面厚硬顶板 超深孔预裂爆破 高威力水胶炸药 爆破致裂机理 安全高效开采
下载PDF
软土地层三线小角度叠交盾构隧道施工影响规律及位移控制
16
作者 程雪松 盛鲁腾 +5 位作者 郑刚 王瑞坤 张雨明 付瑞心 仲志武 杜一鸣 《铁道建筑》 北大核心 2024年第5期123-128,共6页
天津地铁6号线入出段线盾构隧道上穿既有隧道,通过现场实测和数值模拟对既有隧道结构变形规律、变形影响因素、不同变形控制措施的效果进行了研究。结果表明:盾构上穿过程中既有隧道竖向位移整体呈现出隆起-沉降-隆起的变化规律;刀盘距... 天津地铁6号线入出段线盾构隧道上穿既有隧道,通过现场实测和数值模拟对既有隧道结构变形规律、变形影响因素、不同变形控制措施的效果进行了研究。结果表明:盾构上穿过程中既有隧道竖向位移整体呈现出隆起-沉降-隆起的变化规律;刀盘距叠交部位断面距离L=2.0D(D为隧道直径)时,叠交部位断面轴力达到最大值,L=0~2.0D时,叠交部位断面弯矩逐渐由L≤0时的横8字形转变为L≥2.0D时的三叶草形;新建隧道与既有隧道的叠交角度在15°~60°、竖向净距小于1.0D时,既有隧道竖向位移受新建隧道影响较大,实际工程中应使叠交角度大于60°,竖向净距大于1.0D;设置支撑台车后,支撑台车影响范围约为2倍台车长度,在影响范围内横断面位移得到控制,但随着支撑台车离开,原来位置处对位移的控制效果逐渐消失;与不注浆相比,深孔注浆加固后既有隧道竖向位移最大值和水平位移最大值分别减小了67.4%、76.0%。 展开更多
关键词 地铁隧道 三线小角度叠交 现场实测 数值模拟 变形规律 控制措施 支撑台车 深孔注浆
下载PDF
BTA深孔连接器设计及油膜压力研究
17
作者 陈振亚 马卓强 +3 位作者 李翔 苗鸿宾 杨尚进 李建 《机床与液压》 北大核心 2024年第19期59-64,共6页
针对BTA加工过程中刀具系统刚性不足和径向受力不平衡的问题,基于流体动压润滑原理设计一种BTA深孔连接器。连接器包括双桥应变片和可倾瓦块,利用油膜支撑刚度增大刀具系统的刚性,并通过实时调整油膜压力抵消同步检测的不平衡径向力。... 针对BTA加工过程中刀具系统刚性不足和径向受力不平衡的问题,基于流体动压润滑原理设计一种BTA深孔连接器。连接器包括双桥应变片和可倾瓦块,利用油膜支撑刚度增大刀具系统的刚性,并通过实时调整油膜压力抵消同步检测的不平衡径向力。建立可倾瓦块的数学模型,推导出油膜厚度公式,进一步得出油膜压力的计算公式。基于Fluent软件对连接器进行流体仿真,采用单因素实验法,分析不同条件下可倾瓦块受到的油膜压力的变化规律。结果表明:BTA加工过程中,通过调节工件转速、切削液黏度、瓦块倾角和瓦块包角等参数调整油膜压力,进而实现增大刀具系统刚性和抵消不平衡径向力的目的。 展开更多
关键词 BTA深孔连接器 油膜压力 系统刚性 径向力 流体仿真
下载PDF
船闸深孔反弧门实时在线监测技术应用研究
18
作者 张宇 王小林 +1 位作者 方超群 耿红磊 《水利信息化》 2024年第3期55-59,共5页
针对船闸输水系统工作反弧门长期在深孔动水条件下频繁启闭,给船闸安全运行造成安全隐患,提出一种深孔反弧门实时在线监测技术方案。为掌握深孔反弧门运行情况,将已密封好的应变及倾角等传感器布置在闸门上,再利用钢丝网架胶管将采集信... 针对船闸输水系统工作反弧门长期在深孔动水条件下频繁启闭,给船闸安全运行造成安全隐患,提出一种深孔反弧门实时在线监测技术方案。为掌握深孔反弧门运行情况,将已密封好的应变及倾角等传感器布置在闸门上,再利用钢丝网架胶管将采集信号输送至在线监测系统。监测系统实时进行反弧门在线监测与数据显示,并实时分析结构应力、运行姿态及启闭力,根据分析结果,给出不同等级报警信息及相应的处置建议,提示运行操作人员对反弧门采取对应措施。对广西大藤峡水利枢纽船闸反弧门实施实时在线监测,测试数据表明实施的反弧门实时在线监测系统是可靠稳定的,证明将实时在线监测技术应用于深孔且动水频繁启闭的闸门是可行的。 展开更多
关键词 深孔反弧门 实时在线监测技术 安全评价 船闸
下载PDF
深孔轴向多段间隔装药孔壁冲击压力分布
19
作者 楼晓明 唐志恒 +2 位作者 牛明远 林日宗 曾令峰 《矿冶工程》 CAS 北大核心 2024年第1期6-11,共6页
为确定地下垂直长深孔爆破时合理的空气间隔长度,基于爆轰波理论,分析了多段间隔装药爆破条件下孔壁冲击压力随间隔长度变化的内在分布规律函数;依据Mises准则,得出了不同岩性时合理的间隔长度参考值,并通过数值模拟和现场爆破试验进行... 为确定地下垂直长深孔爆破时合理的空气间隔长度,基于爆轰波理论,分析了多段间隔装药爆破条件下孔壁冲击压力随间隔长度变化的内在分布规律函数;依据Mises准则,得出了不同岩性时合理的间隔长度参考值,并通过数值模拟和现场爆破试验进行了验证。结果表明,空气间隔段孔壁冲击压力沿炮孔轴线从两端向中间骤降,但在中点周围略微增大,压力曲线呈两端大、中间小、中点周围略微凸起的“W”形对称分布。 展开更多
关键词 深孔爆破 轴向不耦合装药 空气间隔 孔壁冲击压力 数值模拟
下载PDF
深孔焊结构喷泉式管束装配工艺技术研究
20
作者 杜鑫 程龙 张盛岩 《锅炉制造》 2024年第3期40-42,共3页
深孔焊技术广泛应用于石油化工领域中的重要换热设备,可有效减少间隙腐蚀、应力腐蚀、疲劳破裂等问题。本文针对深孔焊结构喷泉式管束,进行装配工艺技术的研究。
关键词 深孔焊 喷泉式管束 装配
下载PDF
上一页 1 2 193 下一页 到第
使用帮助 返回顶部