Search | Engineering

订阅投稿

首页工程期刊工程焦点工程成就工程前沿关于我们 English

资源类型

期刊论文 992

会议视频 8

年份

2023 67

2022 80

2021 67

2020 71

2019 50

2018 43

2017 43

2016 43

2015 51

2014 43

2013 40

2012 40

2011 34

2010 47

2009 44

2008 39

2007 39

2006 28

2005 29

2004 22

展开︾

关键词

数学模型 13

模型试验 9

数值模拟 8

模型 7

不确定性 5

COVID-19 4

GM(1 3

计算机模拟 3

1)模型 2

DX桩 2

D区 2

Preissmann格式 2

SARS 2

TRIZ 2

Weibull分布 2

k-ε模型 2

不确定性评估 2

临震信号 2

云模型 2

展开︾

检索范围：

排序：展示方式：

Choosing configurations of transmission line tower grounding by back flashover probability value

Dmitry KUKLIN

《能源前沿（英文）》 2016年第10卷第2期页码 213-226 doi: 10.1007/s11708-016-0398-6

摘要： There is a considerable number of works devoted to electrical characteristics of grounding. These characteristics are important in general. However, in application to grounding of transmission line towers they are not enough to determine what grounding construction is preferable in some particular case, because these characteristics are calculated or measured apart from the grounded object, and only limited number of current (or voltage) source waveforms is used. This paper indicates reasons in favor of the fact that to choose the optimum design of grounding, the calculation model should include the tower as it is. The probability of back flashover, which provides both qualitative and quantitative estimate of the grounding structure efficiency, can be taken as the criterion for the grounding design. The insulation flashover probability is calculated on the basis of engineering method, which evaluates breakdown strength of insulation for nonstandard waveshapes, and probability data on lightning currents. Different approaches are examined for identifying the back flashover probability, as not only amplitudes but also other parameters can be taken into account. Finite-difference time-domain method is used for calculations of transients. It is found that lightning current waveform can greatly influence calculated back flashover probability value.

关键词： grounding transmission line tower back flashover probability FDTD method

HTML PDF 收藏

Analytical method of capsizing probability in the time domain for ships in the random beam seas

LIU Liqin, TANG Yougang, LI Hongxia

《结构与土木工程前沿（英文）》 2007年第1卷第3期页码 361-366 doi: 10.1007/s11709-007-0048-5

摘要： The methods for constructing safe basins of ships and predicting their survival probability in random waves were studied. The nonlinear differential equation of the rolling motion of ships in random beam seas was established considering nonlinear damping, nonlinear restoring moment, and random waves. The random rolling differential equation was solved in the time domain by applying the harmonic acceleration method and by synthetically considering the instantaneous state of ships and the narrowband wave energy spectrum. The numerical simulation of random capsizing course was brought forward, the safe basins were constructed for safe navigation, and the survival probabilities of ships were calculated. As an example, the safe basins on the rolling initial value plane were constructed for a 30.27-meter-long fishing vessel according to different initial conditions and random wave parameters. The survival probabilities of the fishing vessel under different significant wave heights were predicted. Thus, the survival probabilities of ships in random seas can be predicted quantitatively by the proposed method.

关键词： different survival probability different significant nonlinear differential narrowband

HTML PDF 收藏

Transmission probability method based on triangle meshes for solving the unstructured geometry neutron

WU Hongchun, LIU Pingping, ZHOU Yongqiang, CAO Liangzhi

《能源前沿（英文）》 2007年第1卷第2期页码 158-166 doi: 10.1007/s11708-007-0020-z

摘要： The fuel assembly or core with unstructured geometry is frequently used in the advanced reactor. To calculate the fuel assembly, the transmission probability method (TPM) is widely used. However, the rectangular or hexagonal meshes are mainly used in the TPM codes for the normal core structure. The triangle meshes are most useful for expressing the complicated unstructured geometry. Even though the finite element method and Monte-Carlo method are well suited for solving the unstructured geometry problem, they are very time-consuming. Therefore, a TPM code based on the triangle meshes is developed here. This code was applied to the hybrid fuel geometry, and compared with the results of the MCNP code and other codes. The results of the comparison were consistent with each other. The TPM with triangle meshes can thus be applied to the two-dimensional arbitrary fuel assembly.

关键词： unstructured geometry assembly transmission probability TPM rectangular

HTML PDF 收藏

庞明慧1,2,朱秋明1,2,林志鹏1,柏菲1,田越1,李茁3,陈小敏1

《信息与电子工程前沿（英文）》 2022年第23卷第9期页码 1378-1389 doi: 10.1631/FITEE.2200041

摘要：视距（line-of-sight, LoS）概率预测对于无线通信系统的性能优化至关重要。然而，由于无人机等飞行器飞行高度从十几米到数千米不等，空地（air-to-ground, A2G）通信的LoS概率预测具有挑战性。本文针对A2G场景，提出一种高度相关的经验性LoS概率模型。在模型参数估计之前，设计了一种基于K近邻（K-nearest neighbors, KNN）的策略对LoS和非视距（none-line-of-sight, NLoS）路径进行分类。然后，开发了一种基于双层反向传播神经网络（back propagation neural network, BPNN）的参数估计方法来建立每个模型参数与无人机高度之间的关系。仿真表明该模型获得的结果与射线追踪（ray trancing, RT）数据、实测数据和标准模型结果具有良好一致性。该模型还可提供比其他LoS概率模型更广泛的适用高度，能够应用于各种A2G场景下的不同通信高度。

关键词：视距概率模型；空地信道；机器学习；射线跟踪

HTML PDF 收藏

Proposal of a probabilistic assessment of structural collapse concomitantly subject to earthquake and gas explosion

Gholamreza ABDOLLAHZADEH, Hadi FAGHIHMALEKI

《结构与土木工程前沿（英文）》 2018年第12卷第3期页码 425-437 doi: 10.1007/s11709-017-0427-5

摘要：

In recent decades, many public buildings, located in seismic-prone residential areas, had to grapple with abnormal loads against which the structures were unguarded. In this piece of research, an ordinary three dimensional reinforced concrete building is selected as case study. The building is located in an earthquake-prone region; however, it is designed according to seismic building codes. Yet, it is not shielded against abnormal loads, such as blasts. It is assumed that the building suffers a blast load, due to mechanical/thermal installation failure during or after intense seismic oscillations. These two critical incidents are regarded codependent and compatible. So the researchers developed scenarios and tried to assess different probabilities for each scenario and carried out an analysis to ensure if progressive collapse had set in or not. In the first step, two analysis models were used for each scenario; a non-linear dynamic time history analysis and a blast local dynamic analysis. In the second step, having the structural destructions of the first step in view, a pushdown analysis was carried out to determine the severity of progressive collapse and assess building robustness. Finally, the annual probability of structural collapse under simultaneous earthquake and blast loads was estimated and offered.

关键词： gas blast pushdown analysis progressive collapse annual probability of structural collapse 3D model of structure

HTML PDF 收藏

A Fast Evaluation and Research Method for Exploration Potential of Oversea Basins

Hong-quan Kang,Yun-hua Deng,Huai-cun Jia,Tao Cheng,Bo Bai

《工程管理前沿（英文）》 2016年第3卷第4期页码 338-342 doi: 10.15302/J-FEM-2016052

摘要： Oversea hydrocarbon exploration always faces some problems, such as multiple basin types, different exploration prospects, various exploration degrees, diverse data quantities and geological recognitions. This paper focuses on overseas basins with different exploration degrees and offers a new evaluation system and research method for fast evaluation and risk analysis on hydrocarbon potential. Based on the theory of probability, this new evaluation system evaluates each parameter and core accumulation factor with comprehensive and quantitative assignment, to accelerate geological evaluation. In addition, this paper suggests that source rock evaluation should be the core criterion in screening evaluation of poor-explored basins, and also proposes that both the exploration potential and geological recognition should drive the evaluation for basins with high exploration degrees. This new system and method, which is an effective system for fast basin evaluation, is suggested to be used in oversea evaluation and decision-making objectively, scientifically and efficiently.

关键词： geological risk analysis probability model evaluation factors oversea exploration hydrocarbon exploration

HTML PDF 收藏

Evaluating effect of chloride attack and concrete cover on the probability of corrosion

Sanjeev Kumar VERMA, Sudhir Singh BHADAURIA, Saleem AKHTAR

《结构与土木工程前沿（英文）》 2013年第7卷第4期页码 379-390 doi: 10.1007/s11709-013-0223-9

摘要： Corrosion of reinforced concrete (RC) structures is one of the significant causes of deterioration of reinforced concrete (RC) structures. Chlorination is a major process governing the initiation and advancement of the injurious corrosion of steel bars. Now, several researches on the chlorination of concrete structures have been ongoing around the world. Present article reviews several recently performed chlorination studies, and from results of a field survey evaluates the effect of chloride content on the probability of corrosion and the influence of concrete compressive strength on the chloride content and penetration, also evaluates the effect of concrete cover over the chloride content of the RC structures at rebar depth and on the probability of corrosion.

关键词： concrete chloride reinforcement corrosion deterioration cover

HTML PDF 收藏

一种考虑概率分布的鲁棒优化模型

丁然,李歧强,张元鹏

《中国工程科学》 2008年第10卷第9期页码 70-73

摘要：

文章以随机规划中的机会约束思想为指导，根据随机参数的概率分布情况，提出了两种鲁棒性条件约束，并在此基础上建立了一种新的鲁棒优化模型，使模型的可行解控制在一定的鲁棒性指标的范围内。该模型不但可处理约束两端同时含有随机参数的情况，还可以方便地推广到非线性模型中。仿真实例说明了模型的有效性。

关键词：不确定性鲁棒优化随机规划机会约束

HTML PDF 收藏

火灾引起的建筑物坍塌概率估算

孙金华,孙占辉,陆守香,范维澄

《中国工程科学》 2003年第5卷第11期页码 51-55

摘要：

为了研究不同防灭火安全措施下火灾引起的建筑结构整体坍塌的概率，对典型建筑物的火灾荷载进行了统计分析。利用建筑物火灾的规律及概率与统计理论，给出了典型建筑物的火灾荷载及火灾持续时间的概率分布函数。分析了由火灾引起建筑物坍塌的影响因素，并根据火灾统计结果，得到了写字楼在极端情况下由火灾引起的楼房坍塌概率与其耐火极限时间的关系，导出了一般建筑由于火灾引起的坍塌概率的简单估算方法。

关键词：建筑物火灾火灾荷载坍塌概率

HTML PDF 收藏

Nonlinear analysis and reliability of metallic truss structures

Karim BENYAHI, Youcef BOUAFIA, Salma BARBOURA, Mohand Said KACHI

《结构与土木工程前沿（英文）》 2018年第12卷第4期页码 577-593 doi: 10.1007/s11709-017-0458-y

摘要： The present study goes into the search for the safety domain of civil engineering structures. The objective is to show how a reliability-evaluation brought by a mechanical sizing can be obtained. For that purpose, it is necessary to have a mechanical model and a reliability model representing correctly the behavior of this type of structure. It is a question on one hand, to propose a formulation for the nonlinear calculation (mechanical nonlinearity) of the spatial structures in trusses, and on the other hand, to propose or to adapt a formulation and a modeling of the reliability. The principle of Hasofer-Lind can be applied, in first approach, for the reliability index estimation, scenarios and the probability of failure. The made check concerned metallic in truss structures. Finally, some structures are calculated using the method adapted by Hasofer-Lind to validate the probability approach of the reliability analysis.

关键词： modeling nonlinearity mechanical truss probability reliability response surface probability of failure

HTML PDF 收藏

Probability strength design of steam turbine blade and sensitivity analysis with respect to random parameters

DUAN Wei

《能源前沿（英文）》 2008年第2卷第1期页码 107-115 doi: 10.1007/s11708-008-0018-1

摘要： Many stochastic parameters have an effect on the reliability of a steam turbine blade during practical operation. To improve the reliability of blade design, it is necessary to take these stochastic parameters into account. An equal cross-section blade is investigated and a finite element model is built parametrically. Geometrical parameters, material parameters and load parameters of the blade are considered as input random variables while the maximum deflection and maximum equivalent stress are output random variables. Analysis file of the blade is compiled by deterministic finite element method and applied to be loop file to create sample points. A quadratic polynomial with cross terms is chosen to regress these samples by step-forward regression method and employed as a surrogate of numerical solver to drastically reduce the number of solvers call. Then, Monte Carlo method is used to obtain the statistical characteristics and cumulative distribution function of the maximum deflection and maximum equivalent stress of the blade. Probability sensitivity analysis, which combines the slope of the gradient and the width of the scatter range of the random input variables, is applied to evaluate how much the output parameters are influenced by the random input parameters. The scatter plots of structural responses with respect to the random input variables are illustrated to analyze how to change the input random variables to improve the reliability of the blade. The results show that combination of the finite element method, the response surface method and Monte Carlo method is an ideal way for the reliability analysis and probability strength design of the blade.

关键词： Probability sensitivity sensitivity analysis number cross-section statistical

HTML PDF 收藏

几率波与量子效应的扭率问题

欧阳首承,李智兰,袁东升

《中国工程科学》 2005年第7卷第6期页码 1-6

摘要：

按曲率空间的扭率，对含有三阶非线性变量导数的Schrödinger变形等价程进行了数值分析，发现几率波的几率性原来是扭率的疏密流在特定条件下的准规则流，并为势场强度和粒子体元密度的相互作用与量子扭率效应项综合作用的结果；纯量子效应作用为非规则流。

关键词：扭率几率量子效应非线性不稳定曲率空间

HTML PDF 收藏

基于适用概率匹配与多维情境驱动的设计知识推送技术 None

Shu-you ZHANG, Ye GU, Xiao-jian LIU, Jian-rong TAN

《信息与电子工程前沿（英文）》 2018年第19卷第2期页码 235-245 doi: 10.1631/FITEE.1700763

摘要：为了提高产品智能设计过程中设计知识的使用效率和质量，有必要向设计人员主动推送设计知识。知识推送主要包括知识匹配和匹配结果的合理推送两个方面。针对现有知识匹配通常缺乏智能性和匹配结果推送缺少个性化的问题，提出基于适用概率匹配和多维情境驱动的设计知识推送技术。构建包括设计知识表示向量、设计案例特征向量和映射布尔矩阵等的训练样本集，通过贝叶斯理论计算设计知识适用与不适用于设计内容的概率，即二者之间的匹配度，得到推送知识集。构建等级化设计内容模型对推送知识集进行过滤，通过设计知识、设计上下文、设计内容和设计人员等多维情境驱动，实现个性化的设计知识推送。在数控机床智能设计平台中的知识推送应用，证明了该技术的可行性和正确性。

关键词：产品设计；知识推送；适用概率匹配；多维情境；个性化

HTML PDF 收藏

基于火灾动力学和概率统计理论耦合的建筑火灾直接损失预估

褚冠全,孙金华

《中国工程科学》 2004年第6卷第8期页码 64-68

摘要：

以火灾成长概率和火灾发生后的过火面积为评价指标，探讨对建筑火灾过火面积的预估方法。依据火灾动力学和火灾发展过程中不同阶段的特点，将火灾由初期发展蔓延到整个防火分区的过程划分为4个阶段，采用概率论和事件树的分析方法，得到了每个阶段的火灾成长概率。根据不同阶段火灾的特点，求得了各阶段火灾的临界时间，并以此为基础对火灾发生后建筑物平均过火面积进行了预估。

关键词：建筑火灾火灾风险评估事件树概率过火面积

HTML PDF 收藏

Reliability design method for steam turbine blades

SHI Jinyuan

《能源前沿（英文）》 2008年第2卷第4期页码 363-368 doi: 10.1007/s11708-008-0073-7

摘要： Based on theories of probability and statistics, and taking static stresses, dynamic stresses, endurance strength, safety ratios, vibration frequencies and exciting force frequencies of blades as random variables, a reliability design method for steam turbine blades is presented. The purport and calculation method for blade reliability are expounded. The distribution parameters of random variables are determined after analysis and numerical calculation of test data. The fatigue strength and the vibration design reliability of turbine blades are determined with the aid of a probabilistic design method and by interference models for stress distribution and strength distribution. Some blade reliability design calculation formulas for a dynamic stress design method, a safety ratio design method for fatigue strength, and a vibration reliability design method for the first and second types of tuned blades and a packet of blades on a disk connected closely, are given together with some practical examples. With these methods, the design reliability of steam turbine blades can be guaranteed in the design stage. This research may provide some scientific basis for reliability design of steam turbine blades.

关键词： design reliability force probability purport reliability design