Seismic design or retrofit of buildings with metallic structural fuses by the damage-reduction spectrum

Recently, the structural fuse has become an important issue in the field of earthquake engineering. Due to the trilinearity of the pushover curve of buildings with metallic structural fuses, the mechanism of the structural fuse is investigated through the ductility equation of a single-degree-of-freedom system, and the corresponding damage-reduction spectrum is proposed to design and retrofit buildings. Furthermore, the controlling parameters, the stiffness ratio between the main frame and structural fuse and the ductility factor of the main frame, are parametrically studied, and it is shown that the structural fuse concept can be achieved by specific combinations of the controlling parameters based on the proposed damage-reduction spectrum. Finally, a design example and a retrofit example, variations of real engineering projects after the 2008 Wenchuan earthquake, are provided to demonstrate the effectiveness of the proposed design procedures using buckling restrained braces as the structural fuses.

Study on detonation velocity deficits of bending flexible detonation fuses

In order to study the detonation velocity deficits of bending flexible detonating fuses,a physical model and a theoretical mathematical equation of detonation velocity deficits for bending flexible detonation fuses were established based on the detonation wave＇s corner effects and delay time phenomenon by using non-dimensional analysis method.Besides,a semi-empirical formula of detonation velocity deficit for bending fuses in the same charge size was obtained through experiment and curve fitting.The result shows that an exponential relationship between the detonation velocity deficits and reciprocal of curvature radius.

Controlled rocking pile foundation system with replaceable bar fuses for seismic resilience

Bridges designed following a conventional approach minimize the risk of collapse,but often require challenging,costly,and time-consuming restoration after an earthquake occurs.The new seismic design philosophy requires bridges to maintain functionality even after severe earthquakes.In this context,this paper proposes a controlled rocking pile foundation(CRPF)system and numerically evaluates bridges′degree of seismic resilience.The CRPF system allows a pile cap to rock on a pile foundation and dissipate seismic energy through inelastic deformations of replaceable bar fuses that connect a pile cap and piles.Following the conceptual design of the CRPF system,two analytical models were developed for a bridge pier utilizing the CRPF system and a pier designed to develop a plastic hinge in its column.The analytical results indicate that,after experiencing a severe earthquake,a conventionally designed bridge pier sustained substantial damage in its column and exhibited significant residual displacement.In contrast,a pier using the CRPF system showed negligible residual displacement and maintained elastic behavior except,as expected,for bar fuses.The damaged fuses can be rapidly replaced to recover bridge seismic resistance following an earthquake.Therefore,the CRPF system helps to achieve the desired postearthquake performance objectives.

Steel rings as seismic fuses for enhancing ductility of cross braced frames

A new remedy is proposed in this study to increase the ductility of cross-braced frames to a level comparable with ductile moment frames.The suggested system consists of one or two concentric steel rings installed in the cross-braced bay vertically.The steel rings are designed such that they fail in bending sooner than failure of the braces in compression.Then the rings act as seismic fuses with multiple bending plastic hinges.Using nonlinear static analysis,it is shown that the proposed system can be designed to behave like cross-braced frames with regard to stiffness and strength,and like special moment frames with regard to ductility.Seismic design factors for the proposed system are recommended based on nonlinear pushover and cyclic analysis studies.

Broken and fine powder detection method of fuses

Since powder and cotton wool may cause mechanical test fail,and the accuracy of ray detection method is not very ideal,this paper introduces the tiny capacitance detection method for broken gunpowder,in which the medium type capacitive sensor’s capacitance changes when the gunpowder core diameter changes.The detection is based on the relationship between non-electric quantity and electric quantity.Simulation results show that the designed system works well with easy installation and low power consumption.Therefore,it is suitable for broken gunpowder detection.

SEPW-the Cradle of Surge Arresters and Fuses in China

Shanghai Electric Porcelain Works (SEPW), a subsidiary enterprise of the SEC (Group), is specialized in manufacturing highvoltage surge arresters and fuses as main products, as well as some high-voltage insulators, wall bushings and disconnecting switches for power transmission & distribution systems. In fact, SEPW is

Design and application of all-fused-ring electron acceptors

Near-infrared(NIR)responsive compounds with narrow bandgaps play a crucial role in enhancing the photovoltaic efficiency of organic solar cells(OSCs)by effectively capturing high-energy NIR photons,as well as improving the NIR sensitivity of organic photodetectors(OPDs)through NIR light detection[1,2].The design principle based on electron-donating and accepting(D−A)structures has led to the development of numerous A−D−A or A−DA’D−A type NIR responsive molecules,such as ITIC and Y6.

Seismic performance evaluation of hybrid coupled shear wall system with shear and flexural fuse-type steel coupling beams

Replaceable flexural and shear fuse-type coupling beams are used in hybrid coupled shear wall(HCSW)systems,enabling concrete buildings to be promptly recovered after severe earthquakes.This study aimed to analytically evaluate the seismic behavior of flexural and shear fuse beams situated in short-,medium-and high-rise RC buildings that have HCSWs.Three building groups hypothetically located in a high seismic hazard zone were studied.A series of 2D nonlinear time history analyses was accomplished in OpenSees,using the ground motion records scaled at the design basis earthquake level.It was found that the effectiveness of fuses in HCSWs depends on various factors such as size and scale of the building,allowable rotation value,inter-story drift ratio,residual drift quantity,energy dissipation value of the fuses,etc.The results show that shear fuses better meet the requirements of rotations and drifts.In contrast,flexural fuses dissipate more energy,but their sectional stiffness should increase to meet other requirements.It was concluded that adoption of proper fuses depends on the overall scale of the building and on how associated factors are considered.

Residual stress modeling of mitigated fused silica damage sites with CO_(2)laser annealing

A numerical model based on measured fictive temperature distributions is explored to evaluate the residual stress fields of CO_(2)laser-annealed mitigated fused silica damage sites.The proposed model extracts the residual strain from the differences in thermoelastic contraction of fused silica with different fictive temperatures from the initial frozen-in temperatures to ambient temperature.The residual stress fields of mitigated damage sites for the CO_(2)laser-annealed case are obtained by a finite element analysis of equilibrium equations and constitutive equations.The simulated results indicate that the proposed model can accurately evaluate the residual stress fields of laser-annealed mitigated damage sites with a complex thermal history.The calculated maximum hoop stress is in good agreement with the reported experimental result.The estimated optical retardance profiles from the calculated radial and hoop stress fields are consistent with the photoelastic measurements.These results provide sufficient evidence to demonstrate the suitability of the proposed model for describing the residual stresses of mitigated fused silica damage sites after CO_(2)laser annealing.

Alkylene-functionality in bridged and fused nitrogen-rich poly-cyclic energetic materials:Synthesis,structural diversity and energetic properties

From the standpoint of chemical structures,the organic backbones of energetic materials can be classified into aromatic rings,nonaromatic rings,and open chains.Although the category of aromatic energetic compounds exhibits several advantages in the regulation of energetic properties,the nonaromatic heterocycles,assembling nitramino explosophores with simple alkyl bridges,still have prevailed in benchmark materials.The methylene bridge plays a pivotal role in the constructions of the classic nonaromatic heterocycle-based energetic compounds,e.g.,hexahydro-1,3,5-trinitro-1,3,5-triazine(RDX)and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine(HMX),whereas ethylene bridge is the core moiety of state-of-the-art explosive 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane(CL-20).In this context,it is of great interest to employ simple and practical bridges to assemble aromatic and nonaromatic nitrogen-rich heterocycles,thereby expanding the structural diversity of energetic materials,e.g.,bridged and fused nitrogen-rich poly-heterocycles.Furthermore,alkyl-bridged poly-heterocycles highlight the potential for the open chain type of energetic materials.In this review,the development of alkyl bridges in linking nitrogen-rich heterocycles is presented,and the perspective of the newly constructed energetic backbones is summarized for the future design of advanced energetic materials.

Research on aiming methods for small sample size shooting tests of two-dimensional trajectory correction fuse

The longitudinal dispersion of the projectile in shooting tests of two-dimensional trajectory corrections fused with fixed canards is extremely large that it sometimes exceeds the correction ability of the correction fuse actuator.The impact point easily deviates from the target,and thus the correction result cannot be readily evaluated.However,the cost of shooting tests is considerably high to conduct many tests for data collection.To address this issue,this study proposes an aiming method for shooting tests based on small sample size.The proposed method uses the Bootstrap method to expand the test data;repeatedly iterates and corrects the position of the simulated theoretical impact points through an improved compatibility test method;and dynamically adjusts the weight of the prior distribution of simulation results based on Kullback-Leibler divergence,which to some extent avoids the real data being"submerged"by the simulation data and achieves the fusion Bayesian estimation of the dispersion center.The experimental results show that when the simulation accuracy is sufficiently high,the proposed method yields a smaller mean-square deviation in estimating the dispersion center and higher shooting accuracy than those of the three comparison methods,which is more conducive to reflecting the effect of the control algorithm and facilitating test personnel to iterate their proposed structures and algorithms.;in addition,this study provides a knowledge base for further comprehensive studies in the future.

Identification of Stability Domains for Flow Parameters in Fused Filament Fabrication Using Acoustic Emission

In Fused Filament Fabrication(FFF),the state of material flow significantly influences printing outcomes.However,online monitoring of these micro-physical processes within the extruder remains challenging.The flow state is affected by multiple parameters,with temperature and volumetric flow rate(VFR)being the most critical.The study explores the stable extrusion of flow with a highly sensitive acoustic emission(AE)sensor so that AE signals generated by the friction in the annular region can reflect the flow state more effectively.Nevertheless,the large volume and broad frequency range of the data present processing challenges.This study proposes a method that initially selects short impact signals and then uses the Fast Kurtogram(FK)to identify the frequency with the highest kurtosis for signal filtration.The results indicate that this approach significantly enhances processing speed and improves feature extraction capabilities.By correlating AE characteristics under various parameters with the quality of extruded raster beads,AE can monitor the real-time state of material flow.This study offers a concise and efficient method for monitoring the state of raster beads and demonstrates the potential of online monitoring of the flow states.

DECISION-MAKING OF SLICING SCHEME IN FUSED DEPOSITION MODELING PROCESS BASED ON ANALYTICAL HIERARCHICAL PROCESS

Based on analyzing the influences of a slicing scheme on stair-stepping effect, supporting structure, efficiency and deformation, etc. , analytical hierarchical process （AHP） combining with fuzzy synthetic evaluation is introduced to make decision in slicing schemes for a processing part. The application in determining the slicing scheme for a computer mouse during prototyping shows that the method increases the rationality during decision- making and improves quality and efficiency for the prototyping part.

基于fused惩罚的稀疏主成分分析

本文旨在研究基于fused惩罚的稀疏主成分分析方法,以适用于相邻变量之间高度相关甚至完全相等的数据情形。首先,从回归分析角度出发,提出一种求解稀疏主成分的简便思路,给出一种广义的稀疏主成分模型——GSPCA模型及其求解算法,并证明在惩罚函数取1-范数时,该模型与现有的稀疏主成分模型——SPC模型的求解结果一致。其次,提出将fused惩罚与主成分分析相结合,得到一种fused稀疏主成分分析方法,并从惩罚性矩阵分解和回归分析两个角度,给出两种模型形式。在理论上证明了两种模型的求解结果是一致的,故将其统称为FSPCA模型。模拟实验显示,FSPCA模型在处理相邻变量之间高度相关甚至完全相等的数据集上表现良好。最后,将FSPCA模型应用于手写数字识别,发现与SPC模型相比,FSPCA模型所提取的主成分具备更好的解释性。

基于Fuse的用户态文件系统的设计

现有的文件系统大都运行在内核态下,与内核紧密结合,导致难以对其进行功能上的扩展。针对内核文件系统的这个问题,本文提出了一个基于Fuse框架实现的用户级文件系统dbfuse。一方面将文件系统从内核态中解放出来;另一方面使用数据库技术有效地保证文件系统数据的完整性和安全性,给数据共享带来的方便。

BacFuse棘突间植入术和后路椎间融合固定术治疗腰椎间盘突出症的对比研究

目的通过与后路椎间融合固定术(PLIF)对比,评价Bac Fuse棘突间植入术治疗腰椎间盘突出症的中短期临床疗效。方法回顾性分析2014年1月至2015年1月符合入组标准的单节段腰椎间盘突出症60例,其中BacFuse组30例,PLIF组30例。统计分析两组的住院时间、手术时间、术中失血量。术前、术后6月的视觉模拟评分(VAS)、日本骨科学会腰痛评分(JOA)、椎间盘后缘高度(PDH)。结果 BacFuse组性别、年龄、手术节段与PLIF组相比较无统计学差异。BacFuse组和PLIF组相比,住院时间较短(t=-10.17,P<0.001),手术时间也较短(t=-28.94,P<0.001),出血量较少(t=-31.03,P<0.001),差异均有统计学意义。术后6月随访两组VAS评分均小于术前(P<0.001),两组术前及术后6个月随访VAS评分差异无统计学意义。术后6月随访两组JOA评分均显著大于术前(P<0.001),两组术前及术后6个月随访JOA评分差异无统计学意义。BacFuse组术前PDH 6.26±1.7 mm,6个月随访8.27±1.9 mm,较术前明显改善(t=-12.347,P<0.001)。PLIF组术前PDH 6.33±1.4 mm,6个月随访8.41±1.4mm,较术前明显改善(t=-14.007,P<0.001)。两组术前及术后6月随访PDH差异无统计学意义(P>0.05)。结论 BacFuse棘突间植入术在与PLIF效果相似的情况下损伤更小,是治疗腰椎间盘突出症的有效微创方法。

针对发动机平面度的二维FusedLASSO多元统计控制图

针对具有二维平面自然顺序关系的多元数据,提出了一种基于二维Fused LASSO回归模型的多元统计过程控制图。由于二维Fused LASSO多元回归模型对相邻系数的差异进行惩罚,因此它对检测出变量间的自然顺序关系非常有效。通过数值仿真实验可以看到,二维Fused LASSO控制图能更加快速有效地检测出具有二维平面自然顺序的多元过程中均值发生的变化,且在偏移量越大的情况下优势更加明显。最后通过对发动机平面度数据的实例验证,给出了二维Fused LASSO控制图的步骤和适用性。

在Android平台上开发FUSE文件系统

提出了一种在Android平台上开发FUSE文件系统的方法,由于默认情况下Android系统并不提供对FUSE功能的支持,因此需要对Android系统内核进行重新配置,并生成相应的动态库文件,为FUSE模块提供所需的运行环境。

A novel fused iron catalyst for ammonia synthesis promoted with rare earth gangue

Rare earth gangue, which mainly consists of mixtures of light rare earths such as lanthana, ceria, neodymium oxide and praseodymium oxide, was used as the promoter of fused iron catalysts for ammonia synthesis. The result showed that the activity of the catalyst promoted with rare earth gangue was comparable with those of commercial iron catalysts with high amount of cobalt. The role of rare earths was owed to their advantages for favoring the deep reduction of the main composite in catalyst, i.e., iron oxide. This fmding indicated that the use of rare earth gangue could decrease the content of cobalt or even completely replace cobalt, which was used to be regarded as unsub- stitutable promoters for high performance ammonia catalyst; therefore, the cost of fused iron catalysts would decrease significantly.