检索结果-南通市图书馆

Deep reinforcement learning-based critical element identification and demolition planning of frame structures

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Structural and Civil Engineering 2022年第11期16卷 1397-1414页

作者： shaojun zhu Makoto OHSAKI Kazuki HAYASHI Shaohan ZONG Xiaonong GUO College of Civil Engineering Tongji UniversityShanghai 200092China Department of Architecture and Architectural Engineering Kyoto UniversityKyoto 615-8540Japan Tongji Lvjian Co. Ltd.Shanghai 200092China

This paper proposes a framework for critical element identification and demolition planning of frame structures.Innovative quantitative indices considering the severity of the ultimate collapse scenario are proposed using reinforcement learning and graph embedding.The action is defined as removing an element,and the state is described by integrating the joint and element features into a comprehensive feature vector for each element.By establishing the policy network,the agent outputs the Q value for each action after observing the state.Through numerical examples,it is confirmed that the trained agent can provide an accurate estimation of the Q values,and handle problems with different action spaces owing to utilization of graph embedding.Besides,different behaviors can be learned by varying hyperparameters in the reward function.By comparing the proposed method and the conventional sensitivity index-based methods,it is demonstrated that the computational cost is considerably reduced because the reinforcement learning model is trained offline.Besides,it is proved that the Q values produced by the reinforcement learning agent can make up for the deficiencies of existing indices,and can be directly used as the quantitative index for the decision-making for determining the most expected collapse scenario,i.e.,the sequence of element removals.

关键词： progressive collapse alternate load path demolition planning reinforcement learning graph embedding

Elevated temperature creep model of parallel wire strands

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Structural and Civil Engineering 2023年第7期17卷 1060-1071页

作者： Yong DU Yongjin WU Abdullahi M.UMAR shaojun zhu College of Civil Engineering Nanjing Tech UniversityNanjing 211816China College of Civil Engineering Tongji UniversityShanghai 200092China*Corresponding author.E-mail:zhushaojun@***

T Parallel wire strands(PWSs),which are widely used in prestressed steel structures,are typically in highstress states.Under fire conditions,significant creep effects occur,reducing the prestress and influencing the mechanical behavior of PWSs.As there is no existing approach to analyze their creep behavior,this study experimentally investigated the elevated temperature creep model of PWSs.A charge-coupled camera system was incorporated to accurately obtain the deformation of the specimen during the elevated temperature creep test.It was concluded that the temperature level had a more significant effect on the creep strain than the stress level,and 450℃ was the key segment point where the creep rate varied significantly.By comparing the elevated temperature creep test results for PWSs and steel strands,it was found that the creep strain of PWSs was lower than that of steel strands at the same temperature and stress levels.The parameters in the general empirical formula,the Bailey–Norton model,and the composite timehardening model were fitted based on the experimental results.By evaluating the accuracy and form of the models,the composite time-hardening model,which can simultaneously consider temperature,stress,and time,is recommended for use in the fire-resistance design of pre-tensioned structures with PWSs.

关键词： parallel wire strands experimental study elevated temperature creep model

Shape optimization of aluminium alloy spherical reticulated shells considering nonlinearities

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Structural and Civil Engineering 2022年第12期16卷 1565-1580页

作者： Wei LIU Lishu XU shaojun zhu Lijuan LI Feng LIU Zhe XIONG School of Civil and Transportation Engineering Guangdong University of TechnologyGuangzhou 510006China School of Advanced Manufacturing Guangdong University of TechnologyJieyang 515231China College of Civil Engineering Tongji UniversityShanghai 200092China Tongji Lvjian Co. LtdShanghai 200092China

This study proposes a shape optimization method for K6 aluminum alloy spherical reticulated shells with gusset joints,considering geometric,material,and joint stiffness nonlinearities.The optimization procedure adopts a genetic algorithm in which the elastoplastic non-linear buckling load is selected as the objective function to be maximized.By confinement of the adjustment range of the controlling points,optimization results have enabled a path toward achieving a larger elastoplastic non-linear buckling load without changing the macroscopic shape of the structure.A numerical example is provided to demonstrate the effectiveness of the proposed method.In addition,the variation in structural performance during optimization is illustrated.Through parametric analysis,practical design tables containing the parameters of the optimized shape are obtained for aluminum alloy spherical shells with common geometric parameters.To explore the effect of material nonlinearity,the optimal shapes obtained based on considering and not considering material non-linear objective functions,the elastoplastic and elastic non-linear buckling loads,are compared.

关键词： shape optimization aluminum alloy spherical reticulated shell non-linear buckling material nonlinearity genetic algorithm

平面三角形桁架和Warren平行弦桁架结构火灾下倒塌预警方法

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

建筑结构学报 2024年第7期45卷 131-142页

作者：李晋宇李国强朱劭骏同济大学土木工程学院上海200092 同济大学土木工程防灾国家重点实验室上海200092

为研究火灾下平面三角形和Warren平行弦钢桁架结构的倒塌预警方法,建立有限元模型研究两类桁架在火灾下的倒塌机理与倒塌模式;在此基础上,研究了两类平面钢桁架在各倒塌模式下关键物理量变化规律,并基于桁架关键节点的位移、位移速率以... 详细信息

为研究火灾下平面三角形和Warren平行弦钢桁架结构的倒塌预警方法,建立有限元模型研究两类桁架在火灾下的倒塌机理与倒塌模式;在此基础上,研究了两类平面钢桁架在各倒塌模式下关键物理量变化规律,并基于桁架关键节点的位移、位移速率以及桁架受火杆件的温度等多参数,提出了火致倒塌分级预警方法。为了科学预测桁架的倒塌剩余时间,采用预警时间比与倒塌剩余时间比两个参数,通过蒙特卡洛采样法得到了具有可靠度意义、可在实际工程中直接使用的时间比数值。并将提出的火灾倒塌预警方法和时间比数值通过真实火灾倒塌试验和数值算例进行验证。结果表明:平面三角形桁架和Warren平行弦桁架呈现转铰型、滑移型、屈曲后转铰型、屈曲后滑移型以及再平衡等多种倒塌模式;当预警时间比的可靠度为70%~80%时,可以较为准确地预测Warren平行弦和平面三角形桁架的实际倒塌剩余时间。

关键词：平面桁架火灾倒塌预警位移位移速率可靠度

Synergistic regulation of hydrophobicity and basicity for copper hydroxide-derived copper to promote the CO_(2)electroreduction reaction

在线全文

学校读者我要写书评

暂无评论

Carbon Energy 2023年第6期5卷 72-81页

作者： Limin Zhou Chenghang Li Jing-Jing Lv Wei Wang shaojun zhu Jun Li Yifei Yuan Zheng-Jun Wang Qingcheng Zhang Huile Jin Shun Wang Wenzhou Key Lab of Advanced Energy Storage and Conversion Zhejiang Province Key Lab of Leather EngineeringCollege of Chemistry and Materials EngineeringWenzhou UniversityWenzhouZhejiangChina Zhejiang Engineering Research Center for Electrochemical Energy Materials and Devices Institute of New Materials and Industrial TechnologiesWenzhou UniversityWenzhouZhejiangChina

A simple method was proposed to activate alkaline Cu(OH)_(2)with an acidic ionomer,Nafion,to regulate its surface microenvironment,including hydrophobicity and local basicity.In particular,the direct complete neutralization reaction between Cu(OH)_(2)and Nafion in aqueous solution induces the exposing of vast anions which can exclude the in-situ-formed hydroxides and raise the local basicity.Remarkably,the optimal Nafionactivated Cu(OH)_(2)-derived Cu can efficiently suppress the hydrogen evolution reaction(HER)and improve the selectivity for multi-carbon products in the CO_(2)electroreduction reaction(eCO_(2)RR).The H2 Faradaic efficiency(FE)decreased to 11%at a current density of 300 mA/cm2(−0.76 V vs.RHE)in a flow cell,while the bare one with H2 had an FE of 40%.The total eCO_(2)RR FE reaches as high as 83%,along with an evidently increased C2H4 FE of 44%as compared with the bare one(24%),and good stability(8000 s),surpassing that of most of the reported Cu(OH)_(2)-derived Cu.The experimental and theoretical results both show that the strong hydrophobicity and high local basicity jointly boosted the eCO_(2)RR as acquired by felicitously introducing ionomer on the Cu(OH)_(2)-derived Cu surface.

关键词： CO_(2)electroreduction reaction Cu(OH)_(2)@Nafion flow cell ionomers multi-carbon products

单层网壳结构初始几何缺陷场模拟方法研究进展

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

建筑钢结构进展 2024年第5期26卷 12-21页

作者：曾强朱劭骏杨旭吴晨宇同济大学土木工程学院上海200092 上海建工四建集团有限公司上海201103

单层网壳结构的安全性很大程度上取决于其稳定承载力,而其制作及安装过程中产生的节点几何偏差初始缺陷对其稳定承载力具有重大影响。对单层网壳结构初始几何缺陷场模拟方法的研究进展和现行规范的规定进行了系统综述和分析,结果表明既... 详细信息

单层网壳结构的安全性很大程度上取决于其稳定承载力,而其制作及安装过程中产生的节点几何偏差初始缺陷对其稳定承载力具有重大影响。对单层网壳结构初始几何缺陷场模拟方法的研究进展和现行规范的规定进行了系统综述和分析,结果表明既有的随机性模拟法、确定性模拟法和半随机性模拟法均存在一定问题,规范所推荐的初始缺陷模拟方法脱离实际,因而无法准确确定单层网壳结构稳定承载力的真实概率模型。因此,亟待提出一种考虑结构拓扑约束、基本假定合理、计算成本可控的初始几何缺陷场模拟方法,为完善单层网壳结构整体稳定分析方法提供科学依据,并为分析其稳定可靠度提供理论基础。

关键词：单层网壳初始几何缺陷模拟方法稳定承载力

Injectable Self‑Healing Adhesive pH‑Responsive Hydrogels Accelerate Gastric Hemostasis and Wound Healing

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2021年第5期13卷 118-134页

作者： Jiahui He Zixi Zhang Yutong Yang Fenggang Ren Jipeng Li shaojun zhu Feng Ma Rongqian Wu Yi Lv Gang He Baolin Guo Dake Chu Department of Gastroenterology The First Affiliated Hospital of Xi’an Jiaotong UniversityXi’anPeople’s Republic of China Frontier Institute of Science and Technology and State Key Laboratory for Mechanical Behavior of MaterialsXi’an Jiaotong UniversityXi’an 710049China Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research College of StomatologyXi’an Jiaotong UniversityXi’an 710049People’s Republic of China Department of Dermatology The First Affiliated Hospital of Xi’an Jiaotong UniversityXi’an 710049People’s Republic of China National Local Joint Engineering Research Center for Precision Surgery and Regenerative Medicine and Surgical Engineering Research Center of Shaanxi Province First Affiliated Hospital of Xi’an Jiaotong UniversityXi’anPeople’s Republic of China Department of Experimental Surgery Xijing HospitalFourth Military Medical UniversityXi’anPeople’s Republic of China Department of Pathology Tangdu HospitalFourth Military Medical UniversityXi’anPeople’s Republic of China

Endoscopic mucosal resection(EMR)and endoscopic submucosal dissection(ESD)are well-established therapeutics for gastrointestinal neoplasias,but complications after EMR/ESD,including bleeding and perforation,result in additional treatment morbidity and even threaten the lives of patients.Thus,designing biomaterials to treat gastric bleeding and wound healing after endoscopic treatment is highly desired and remains a challenge.Herein,a series of injectable pH-responsive selfhealing adhesive hydrogels based on acryloyl-6-aminocaproic acid(AA)and AA-g-N-hydroxysuccinimide(AA-NHS)were developed,and their great potential as endoscopic sprayable bioadhesive materials to efficiently stop hemorrhage and promote the wound healing process was further demonstrated in a swine gastric hemorrhage/wound model.The hydrogels showed a suitable gelation time,an autonomous and efficient self-healing capacity,hemostatic properties,and good biocompatibility.With the introduction of AA-NHS as a micro-cross-linker,the hydrogels exhibited enhanced adhesive strength.A swine gastric hemorrhage in vivo model demonstrated that the hydrogels showed good hemostatic performance by stopping acute arterial bleeding and preventing delayed bleeding.A gastric wound model indicated that the hydrogels showed excellent treatment effects with significantly enhanced wound healing with type I collagen deposition,α-SMA expression,and blood vessel formation.These injectable self-healing adhesive hydrogels exhibited great potential to treat gastric wounds after endoscopic treatment.

关键词： Injectable self-healing hydrogel Adhesive hydrogel Gastric hemostasis Gastric wound healing Endoscopic treatment

在线全文

学校读者我要写书评

暂无评论

基于多目标线性规划的本体冲突消除方法

计算机应用与软件 2024年第2期41卷 286-292,310页

作者：彭蔚吴茂念郝秀兰朱绍军郑博湖州师范学院信息工程学院浙江湖州313000 浙江省现代农业资源智慧管理与应用研究重点实验室浙江湖州313000

针对本体逻辑冲突消除传统方法未充分利用本体逻辑性质的缺陷,引入Shapley值法刻画本体逻辑性质,构建基于多目标0-1整数线性规划的本体冲突消除方法,使用分层序列法求解多目标线性规划模型。其解遵循理性放弃原则,避免传统方法中目标权... 详细信息

针对本体逻辑冲突消除传统方法未充分利用本体逻辑性质的缺陷,引入Shapley值法刻画本体逻辑性质,构建基于多目标0-1整数线性规划的本体冲突消除方法,使用分层序列法求解多目标线性规划模型。其解遵循理性放弃原则,避免传统方法中目标权重的平均性或随机性。实验结果表明,采用该方法能够令解集遵循理性放弃原则的前提下,利用本体逻辑性质有效减少解集数量,从而提高决策效率。

关键词：本体逻辑冲突多目标整数线性规划最小不可满足子集 Shapley值法

模块化钢结构建筑平面布局方案智能生成式设计方法

在线全文

学校读者我要写书评

暂无评论

建筑钢结构进展 2024年第2期26卷 83-89,103页

作者：常明媛朱劭骏陈韬陈琛钱昆王一凡中建科工集团有限公司广东深圳518054 同济大学土木工程学院上海200092 上海同济绿建土建结构预制装配化工程技术有限公司上海200092

为研究模块化钢结构建筑平面布局方案的智能生成式设计方法,分别基于平面可行域的有限离散化、不同的变量定义方法、约束条件和目标函数,形成了多目标非线性约束整数规划问题和线性整数规划问题,并分别提出了基于遗传算法和平面密铺算... 详细信息

为研究模块化钢结构建筑平面布局方案的智能生成式设计方法,分别基于平面可行域的有限离散化、不同的变量定义方法、约束条件和目标函数,形成了多目标非线性约束整数规划问题和线性整数规划问题,并分别提出了基于遗传算法和平面密铺算法的求解方法。通过一例基于L形平面可行域的数值算例,阐释了所提出方法的可行性和有效性。数值算例结果表明,在相同目标函数下的模块化钢结构建筑布局方案最优解不唯一;基于遗传算法的智能生成式方法可在较小的计算代价下得到较优的可行解,并可为模块单元尺寸的选型提供依据;基于平面密铺算法的智能生成式方法适应于不同的模块单元集,并在给定模块类型的基础上给出模块单元总数最低的布局方案。通过对比2种智能生成式方法的寻优结果,建议采用基于遗传算法的智能生成式方法初步确定模块单元的尺寸,并进一步结合2种智能生成式算法求解不同的最优平面布局方案。

关键词：模块化钢结构建筑平面布局自动生成遗传算法密铺