Civil Engineering Design最新文献_第4页

Curved beams with circular cross-sections under pure in-plane bending 纯面内弯曲下具有圆形截面的弯曲梁

Civil Engineering Design Pub Date : 2022-03-24 DOI: 10.1002/cend.202100036

Dimitrios S. Sophianopoulos, George T. Michaltsos

引用次数: 0

Multi-scale composite finite element modeling of three-dimensional prestressed reinforced concrete structural members: Part I—A comprehensive framework 三维预应力钢筋混凝土结构构件的多尺度复合有限元建模:第一部分-综合框架

Civil Engineering Design Pub Date : 2022-03-21 DOI: 10.1002/cend.202100042

Guillermo Díaz

{"title":"Multi-scale composite finite element modeling of three-dimensional prestressed reinforced concrete structural members: Part I—A comprehensive framework","authors":"Guillermo Díaz","doi":"10.1002/cend.202100042","DOIUrl":"10.1002/cend.202100042","url":null,"abstract":"The goal of this work is to develop a complete theoretical framework for the numerical modeling of three-dimensional prestressed reinforced concrete structural members, soil mixture, and their interactions. This numerical formulation is based on the construction of a new composite finite element, in order to tackle the multi-scale problem. For this purpose, the mechanical behavior of each microstructure component material will be modeled as follows: (a) for the plain concrete (PC) and the soil mixture, an anisotropic-damage-elastoplastic model equipped with the strong discontinuity approach will be taken into account; (b) a polycrystal plasticity model, for the steel rebars and prestrssed tendons will be captured through a new strategy solution of discontinuous bifurcation problem, with the main objective to represent the multi-cracking phenomenon; (c) regarding the mechanical behavior of the aggregates and rocks (skeleton—hydro mechanic problem) in the PC and soil mixture, respectively, an anisotropic-damage-double-poro-polycrystal plasticity model equipped with softening material will be considered. An advanced failure algorithm based on the marching tetrahedron and the pseudo-termic problem will be developed. Finally, the zone that characterizes the interaction between the structural member and the soil mixture will be encrusted inside the composite finite element.","PeriodicalId":100248,"journal":{"name":"Civil Engineering Design","volume":"4 1-3","pages":"43-61"},"PeriodicalIF":0.0,"publicationDate":"2022-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86340428","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Investigation of a large-scale adaptive concrete beam with integrated fluidic actuators 集成流体作动器的大型自适应混凝土梁研究

Civil Engineering Design Pub Date : 2022-03-19 DOI: 10.1002/cend.202100037

Timon Burghardt, Christian Kelleter, Matthias Bosch, Markus Nitzlader, Matthias Bachmann, Hansgeorg Binz, Lucio Blandini, Werner Sobek

{"title":"Investigation of a large-scale adaptive concrete beam with integrated fluidic actuators","authors":"Timon Burghardt, Christian Kelleter, Matthias Bosch, Markus Nitzlader, Matthias Bachmann, Hansgeorg Binz, Lucio Blandini, Werner Sobek","doi":"10.1002/cend.202100037","DOIUrl":"10.1002/cend.202100037","url":null,"abstract":"As the world population keeps growing, so does the demand for new construction. Considering material resources are limited, it will be unfeasible to meet such demand employing conventional construction methods. A new resource-saving approach is provided by adaptive structures. Using sensors, actuators and control units, structures are enabled to adapt to loads, for example, to compensate for deformations. Since deformations are dominant in the design of bending-stressed load-bearing structures, adaptivity enables such structures to be realized using less material and achieving the same load-bearing capacity in comparison to conventional designs. This article presents a concrete beam of typical building dimensions that compensates deflections by means of integrated fluidic actuators. These actuators offer the possibility of reacting optimally to general loading. The investigation is carried out on an approximately 4-m-long beam with integrated hydraulic actuators. To ensure the overall functionality, accurate dimensioning of the beam as well as the hydraulic system is mandatory. Analytical design of the beam and actuation system are carried out for predimensioning. Experimental testing validates the function and demonstrates that the adaptive beam works as predicted. A fully compensation in deflection is possible. Therefore, a significant increase in load-bearing capacity is possible with the same material input compared to conventional beams.","PeriodicalId":100248,"journal":{"name":"Civil Engineering Design","volume":"4 1-3","pages":"35-42"},"PeriodicalIF":0.0,"publicationDate":"2022-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/cend.202100037","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86036095","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 7

Threaded rods grouted in beech laminated veneer lumber 螺纹杆灌浆在山毛榉层压单板木材

Civil Engineering Design Pub Date : 2022-03-10 DOI: 10.1002/cend.202100041

Jonas Wirries, Franck Y. T. Tsopjio, Till Vallée, Sebastian Myslicki

{"title":"Threaded rods grouted in beech laminated veneer lumber","authors":"Jonas Wirries, Franck Y. T. Tsopjio, Till Vallée, Sebastian Myslicki","doi":"10.1002/cend.202100041","DOIUrl":"10.1002/cend.202100041","url":null,"abstract":"Glued-in rods are a class of adhesively bonded joints for timber engineering applications resulting in high-strength and stiffness connections. However, the use of polymeric adhesives may lead to issues related if the temperatures exceed their glass transition temperature, restricting their performance under quasi-static, or more critically, sustained loads. To overcome these, the substitution of polymeric adhesives by mineral high-performance grout was investigated. It was found that primers have neither a significant effect on strength nor on the failure mode; threated wood surfaces, however, resulted in a significant improvement of the latter. Based thereupon, grouted-in rods were manufactured. The best performance was achieved with a threaded wood surface, which achieved roughly 50% of the strength comparable adhesively bonded glued-in rod's strength. While the obtained strength may seem quite low, it is important to remind that the latter will largely remain unaffected by temperature; accordingly, made at room temperature, the comparison between grouted and glued rods is in favor of adhesive bonding, it may well be different at elevated ones.","PeriodicalId":100248,"journal":{"name":"Civil Engineering Design","volume":"4 4","pages":"110-119"},"PeriodicalIF":0.0,"publicationDate":"2022-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88414946","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Volumetric intersections: Modularization approaches for freeform prefab concrete construction 体积交叉点:自由形式预制混凝土结构的模块化方法

Civil Engineering Design Pub Date : 2022-03-03 DOI: 10.1002/cend.202100047

David Stieler, Tobias Schwinn, Achim Menges

引用次数: 1

Monitoring the microstructural deterioration of concrete exposed to leaching in purified water 纯净水浸出混凝土微观结构劣化的监测

Civil Engineering Design Pub Date : 2021-12-15 DOI: 10.1002/cend.202100051

Robert Schulte Holthausen, Melanie Merkel, Wolfgang Breit, Michael Raupach

{"title":"Monitoring the microstructural deterioration of concrete exposed to leaching in purified water","authors":"Robert Schulte Holthausen, Melanie Merkel, Wolfgang Breit, Michael Raupach","doi":"10.1002/cend.202100051","DOIUrl":"10.1002/cend.202100051","url":null,"abstract":"Concrete is considered to be durable in permanent contact with water, making it a preferred material for the construction of drinking water reservoirs. More severe conditions, however, such as contact with purified water lead to the leaching of calcium and the deterioration of concrete surfaces. Due to the diffusive nature, deterioration begins superficially and ingresses with time. Consequently, concrete surfaces are severely damaged and the rebar-protective alkalinity can be lost. In this study, results from long-term laboratory leaching experiments in purified water of differently prepared concrete surfaces relevant for drinking water reservoirs are reported. Samples are monitored by both conventional laboratory techniques and, for the first time, by single-sided 1H nuclear magnetic resonance to gain knowledge on appearance and performance as well as the microstructural changes with sub-millimeter depth resolution. Results give a deepened insight into the time- and depth-depending material changes. Concrete with a lower w/c ratio, more durable cement, or a densified surface shows a slowed deterioration. The progressing leaching deterioration is described using a combined diffusion-erosion model that allows a more direct comparison of results to other exposures.","PeriodicalId":100248,"journal":{"name":"Civil Engineering Design","volume":"4 4","pages":"99-109"},"PeriodicalIF":0.0,"publicationDate":"2021-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85873302","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Crack width verification and minimum reinforcement according to EC 2: Current model with specifications in Germany and Austria vs proposal for revision 根据EC 2的裂缝宽度验证和最小加固:德国和奥地利规范的当前模型与修订建议

Civil Engineering Design Pub Date : 2021-12-15 DOI: 10.1002/cend.202100045

Nguyen Viet Tue, Ekkehard Fehling, Dirk Schlicke, Christina Krenn

{"title":"Crack width verification and minimum reinforcement according to EC 2: Current model with specifications in Germany and Austria vs proposal for revision","authors":"Nguyen Viet Tue, Ekkehard Fehling, Dirk Schlicke, Christina Krenn","doi":"10.1002/cend.202100045","DOIUrl":"10.1002/cend.202100045","url":null,"abstract":"Limiting crack widths to an acceptable level and determining the required minimum reinforcement are important tasks in the design of reinforced and prestressed concrete structures. Experience with different types of structures, ranging from watertight concrete structures to prestressed concrete bridges, shows that the concept currently applied in Germany and Austria is very effective and that significant changes are not necessary. The current draft for the revision of the EC2 (prEC2), however, presents a new concept for crack width verification and minimum reinforcement. In contrast to the concept currently used in Germany and Austria, this new concept is based more on the analysis and good reproduction of observations made in laboratory experiments and takes less account of the mechanical relationships of reinforced or prestressed concrete after cracking. For this purpose, numerous empirical factors are introduced which not only complicate the understanding but also the application in practice. However, an improvement in the accuracy of the crack width prediction is not achieved and the minimum reinforcement is significantly underestimated, especially for prestressed cross sections and thick members. In this article, the new concept set out in prEC2 is explained in detail. Its main weaknesses and contradictions are discussed by a comparison with the concept currently applied in Germany and Austria as well as detailed analysis of 2D FEM simulations with discrete cracks and adequate regard of the bond stress-slip relationship at the reinforcement-concrete interface. This should provide the basis for a factual discussion before the introduction of prEC2 into practice.","PeriodicalId":100248,"journal":{"name":"Civil Engineering Design","volume":"3 5-6","pages":"210-228"},"PeriodicalIF":0.0,"publicationDate":"2021-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/cend.202100045","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86366536","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Influences on the structural response of beams in drop tower experiments 落塔试验对梁结构响应的影响

Civil Engineering Design Pub Date : 2021-11-03 DOI: 10.1002/cend.202100040

Lena Leicht, Birgit Beckmann, Manfred Curbach

引用次数: 2

Experimental and numerical determination of the screw deformation in laminated beech veneer lumber as a result of moisture-induced swelling 湿胀引起的山毛榉胶合板螺旋变形的实验和数值测定

Civil Engineering Design Pub Date : 2021-10-31 DOI: 10.1002/cend.202100016

Daniela Gerstorfer, Thomas Forte, Josef Füssl

{"title":"Experimental and numerical determination of the screw deformation in laminated beech veneer lumber as a result of moisture-induced swelling","authors":"Daniela Gerstorfer, Thomas Forte, Josef Füssl","doi":"10.1002/cend.202100016","DOIUrl":"10.1002/cend.202100016","url":null,"abstract":"The strong hygroscopic behavior of wood can lead to severe moisture-induced swelling deformations, especially perpendicular to the grain direction. Fully threaded screws arranged in this direction can be used as reinforcement and to constrain those deformations. Depending on the wood moisture content increase, tensile stresses in the screws and compression stresses in the surrounding solid wood evolve. A sufficiently accurate prediction of the maximum stresses occurring is important for reliable structural designs. For this reason, moisture-induced swelling experiments for two different configurations of screw diameter and specimen dimensions were performed within this work. Due to its homogeneity and its high swelling rate perpendicular to the grain, beech laminated veneer lumber (LVL) was used. A moisture content increase from oven-dry to about 7% led to screw tensile stresses in the magnitude of the yield strength and to highly nonlinear effects in the surrounding wood material. By means of a two-dimensional finite-element-based numerical simulation model, taking into account orthotropic plasticity and moisture-dependent material properties, the experiments could be simulated with high accuracy. The numerical results agree well with experimental observations. Based on a small parameter study, new insights into the complex interaction behavior between beech LVL and fully threaded screws could be gained.","PeriodicalId":100248,"journal":{"name":"Civil Engineering Design","volume":"3 5-6","pages":"171-178"},"PeriodicalIF":0.0,"publicationDate":"2021-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81763300","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

An innovative resource-efficient timber-concrete-composite ceiling system: Feasibility and environmental performance 一种创新的资源高效的木材-混凝土复合天花板系统:可行性和环保性能

Civil Engineering Design Pub Date : 2021-10-19 DOI: 10.1002/cend.202100022

Benjamin Kromoser, Philipp Holzhaider

引用次数: 1