WIT Transactions on the Built Environment最新文献_第9页

ASSESSMENT OF COUPLED LAGRANGIAN–EULERIAN FINITE ELEMENT SIMULATIONS TO MODEL SUCTION FORCES DURING HYDRODYNAMIC IMPACTS 耦合拉格朗日-欧拉有限元模拟在流体动力冲击过程中吸力模型的评估

WIT Transactions on the Built Environment Pub Date : 2022-09-19 DOI: 10.2495/hpsu220101

Mathieu Goron, B. Langrand, T. Fourest, N. Jacques, A. Tassin

{"title":"ASSESSMENT OF COUPLED LAGRANGIAN–EULERIAN FINITE ELEMENT SIMULATIONS TO MODEL SUCTION FORCES DURING HYDRODYNAMIC IMPACTS","authors":"Mathieu Goron, B. Langrand, T. Fourest, N. Jacques, A. Tassin","doi":"10.2495/hpsu220101","DOIUrl":"https://doi.org/10.2495/hpsu220101","url":null,"abstract":"During the emergency landing of an aircraft on water, the structure may experience critical forces and could eventually fail. The appropriate design of the structure should minimize the risk of occupant injuries. The recent progress in computation capabilities led to the increased use of numerical simulations in the certification process of aircraft. A specific challenge concerns the modelisation of suction forces that develop near the aircraft tail, where the first contact with water occurs. This phenomenon is due to the high horizontal velocity of the structure at impact and the longitudinal curvature of the fuselage. It can affect the overall aircraft kinematics during ditching. In this work, as an effort to improve aircraft ditching simulations and to assess the capabilities of numerical models to describe suction forces, the simple test case of the wedge water entry and subsequent exit is considered. Numerical simulations with the Eulerian formulation for the fluid and the Lagrangian formulation for the structure are used. The method used for the fluid–structure interaction is based on an immersed contact interface with penalty forces. The present work focuses on impact and suction forces modelling. Results show a satisfying capacity of the numerical approach to model negative hydrodynamic force (suction).","PeriodicalId":23773,"journal":{"name":"WIT Transactions on the Built Environment","volume":"34 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86403643","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

ENGINEERING APPROACH TO CALIBRATE A CONCRETE MODEL FOR HIGH SPEED IMPACT APPLICATIONS 为高速冲击应用校准具体模型的工程方法

WIT Transactions on the Built Environment Pub Date : 2022-09-19 DOI: 10.2495/hpsu220111

Hakim Abdulhamid, P. Deconinck, J. Mespoulet

{"title":"ENGINEERING APPROACH TO CALIBRATE A CONCRETE MODEL FOR HIGH SPEED IMPACT APPLICATIONS","authors":"Hakim Abdulhamid, P. Deconinck, J. Mespoulet","doi":"10.2495/hpsu220111","DOIUrl":"https://doi.org/10.2495/hpsu220111","url":null,"abstract":"This paper describes a study on the mechanical response of concrete under high-velocity impact. It encompasses both experiments and numerical simulations. The aim is to validate an approach for building a concrete numerical model sufficiently robust and accessible to be used for designing civil or defense infrastructures. A conventional concrete (35 MPa compressive strength) has been chosen to apply the method. Experimental tests are conducted to characterize the material in compression and to measure its residual strength during compaction. Impact tests of a kinetic energy projectile (KEP) with an ogive shape nose are also conducted at velocities ranging from 200 to 900 m/s to reproduce both subsonic and supersonic impact conditions. The effect of the concrete confinement is investigated by varying the thickness of a metal jacket surrounding the impacted specimen. Regarding the numerical model, a Holmquist–Johnson–Cook (HJC) for concrete has been calibrated from the measured data. Simulations of the impact perforation are conducted with the γ-SPH solver available in IMPETUS AFEA TM . The numerical model has been able to reproduce the main damage in the concrete during the projectile penetration. Good correlation in terms of deceleration profile during penetration is obtained with the experiment. Moreover, the model is robust enough to reproduce the effects of the confinement variation in the projectile residual velocity. This methodology could be applied to other types of concrete materials subjected to various loadings such as near-field blast for example.","PeriodicalId":23773,"journal":{"name":"WIT Transactions on the Built Environment","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91289414","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

STRUCTURAL TOPOLOGY OPTIMIZATION WITH HIGH SPATIAL DEFINITION BY USING THE OVERWEIGHT APPROACH 基于超重方法的高空间清晰度结构拓扑优化

WIT Transactions on the Built Environment Pub Date : 2022-09-19 DOI: 10.2495/hpsu220071

Diego Villalba, J. París, I. Couceiro, F. Navarrina

{"title":"STRUCTURAL TOPOLOGY OPTIMIZATION WITH HIGH SPATIAL DEFINITION BY USING THE OVERWEIGHT APPROACH","authors":"Diego Villalba, J. París, I. Couceiro, F. Navarrina","doi":"10.2495/hpsu220071","DOIUrl":"https://doi.org/10.2495/hpsu220071","url":null,"abstract":"The first formulation of topology optimization was proposed in the 1980s. Since then, many contributions have been presented with the purpose of improving its efficiency and expanding its field of application. The aim of this research is to develop a structural topology optimization algorithm considering minimum weight and stress constraints. Structural topology optimization with stress constraints has been previously formulated with several different approaches, mainly: local stress constraints, global stress constraints or block aggregation of stress constraints. In this research the overweight approach, an improvement of the so-called damage approach, is used. In this method, a virtual relative density (VRD) is defined as a function of the violation of the local stress constraints. VRD is increased as the stresses exceed the maximum allowable value, with the exception of the areas with the minimum value of the relative density, since full-void solutions are intended. The distribution of the material in the domain is modelled using two different approaches: a uniform relative density within each element of the mesh and a relative density defined by means of quadratic B-splines. For this reason, the structural analysis is performed by means of the finite element method (FEM) and the isogeometric analysis (IGA) respectively. The optimization is addressed by means of the sequential linear programming algorithm (SLP), which is driven by the information provided by a full first order sensitivity analysis extension of both FEM and IGA formulations. Finally, the overweight approach is tested by means of some two dimensional problems. The domain has been divided in an elevated number of elements to attain high spatial definition solutions. The results show that the overweight approach is a feasible alternative for the damage approach and the stress constraints aggregation techniques to solve the topology optimization problem. A comparison between both formulations of the material distribution is included.","PeriodicalId":23773,"journal":{"name":"WIT Transactions on the Built Environment","volume":"57 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83424390","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

OPTIMUM DESIGN OF CABLE-STAYED BRIDGES CONSIDERING CABLE FAILURE 考虑缆索破坏的斜拉桥优化设计

WIT Transactions on the Built Environment Pub Date : 2022-09-19 DOI: 10.2495/hpsu220051

Noel Soto, C. Cid, A. Baldomir, S. Hernández

引用次数: 0

FULL-SCALE REINFORCED CONCRETE SLABS WITH EXTERNAL REINFORCED POLYMER: FIELD TEST AND NUMERICAL COMPARISON 外加筋聚合物全尺寸钢筋混凝土板:现场试验与数值比较

WIT Transactions on the Built Environment Pub Date : 2022-09-19 DOI: 10.2495/hpsu220121

R. Castedo, Anastasio P. Santos, C. Reifarth, M. Chiquito, Lina María López, A. Pérez-Caldentey, S. Martínez-Almajano, A. Alañón

{"title":"FULL-SCALE REINFORCED CONCRETE SLABS WITH EXTERNAL REINFORCED POLYMER: FIELD TEST AND NUMERICAL COMPARISON","authors":"R. Castedo, Anastasio P. Santos, C. Reifarth, M. Chiquito, Lina María López, A. Pérez-Caldentey, S. Martínez-Almajano, A. Alañón","doi":"10.2495/hpsu220121","DOIUrl":"https://doi.org/10.2495/hpsu220121","url":null,"abstract":"Numerical simulation of reinforced concrete (RC) slabs with the addition of an external reinforced polymer (FRP) have been developed and compared with full scale real tests. The size of the slabs was 4.4 x 1.46 m, with a span of 4 m, and a thickness of 15 cm. The slabs were built using concrete of class C25/30, and B500C reinforcing steel. Seven tests were conducted, one at a scaled distance of 0.83 m/kg 1/3 , three at a scaled distance of 0.42 m/kg 1/3 , and three at 0.21 m/kg 1/3 . For the biggest scaled distance, the slab had no extra reinforcement. In the other two cases one of the slabs had no extra reinforcement, while the other two tests were performed with carbon fibre reinforcement (CFRP) and E-glass fibre reinforcement (GFRP) located on the face opposite to the blast. Numerical simulation was performed with LS-DYNA software. The study elements (concrete, steel and reinforcement) have been simulated in a Lagrangian formulation with solid elements, beam elements and shells, respectively. Three concrete models have been used and compared: CSCM, MAT72-R3 and RHT. As for the explosive, the CONWEP-based Load Blast Enhanced (LBE) card was used. Reinforcement with CFRP resulted in a generally reduced damage area on both surfaces. All models show a good correlation with the test results and a non-destructive damage estimation technique when comparing them in terms of damage area.","PeriodicalId":23773,"journal":{"name":"WIT Transactions on the Built Environment","volume":"98 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85257024","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

GROUP ANALYTIC NETWORK PROCESS FOR THE SUSTAINABILITY ASSESSMENT OF BRIDGES NEAR SHORE 近岸桥梁可持续性评价的群分析网络方法

WIT Transactions on the Built Environment Pub Date : 2022-09-19 DOI: 10.2495/hpsu220131

Ignacio J. Navarro, J. Martí, V. Yepes

{"title":"GROUP ANALYTIC NETWORK PROCESS FOR THE SUSTAINABILITY ASSESSMENT OF BRIDGES NEAR SHORE","authors":"Ignacio J. Navarro, J. Martí, V. Yepes","doi":"10.2495/hpsu220131","DOIUrl":"https://doi.org/10.2495/hpsu220131","url":null,"abstract":"Since the Paris Agreement was established, great interest has arisen in evaluating the sustainability performance of our structures along with their life cycles. The remarkable economic expenses, the important environmental impacts associated with the construction sector, and the great social benefits that might be derived from a well-designed infrastructure system have put the design of essential infrastructures in the spotlight of many researchers. One of today’s main challenges is the derivation of adequate sustainability indicators that aid designers when deciding on the most sustainable design alternative. The sustainability performance of infrastructures is based on various indicators that are often conflicting given their different nature. Consequently, the obtention of such indicators usually needs to be addressed using multi-criteria decision-making methods. The present communication shows the analytic hierarchy process (ANP) for the sustainability assessment of a concrete bridge exposed to a coastal environment, involving several decision-makers. A set of nine quantitative criteria, covering the economic, environmental, and social dimensions of sustainability, has been considered here.","PeriodicalId":23773,"journal":{"name":"WIT Transactions on the Built Environment","volume":"62 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73137583","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: 1

KINETIC STREET FURNITURE WITH ARM-Z 带有z臂的动感街道家具

WIT Transactions on the Built Environment Pub Date : 2022-09-19 DOI: 10.2495/hpsu220021

Ela Zawidzka, M. Zawidzki

引用次数: 0

INFLUENCE OF THE PROJECTILE SHAPE ON THE DYNAMIC TENSILE CHARACTERIZATION OF CONCRETE USING A SPLIT HOPKINSON BAR 弹丸形状对劈裂霍普金森杆混凝土动态拉伸特性的影响

WIT Transactions on the Built Environment Pub Date : 2022-09-19 DOI: 10.2495/hpsu220141

M. Ruiz-Ripoll, Victor Rey DE PEDRAZA, C. Roller

{"title":"INFLUENCE OF THE PROJECTILE SHAPE ON THE DYNAMIC TENSILE CHARACTERIZATION OF CONCRETE USING A SPLIT HOPKINSON BAR","authors":"M. Ruiz-Ripoll, Victor Rey DE PEDRAZA, C. Roller","doi":"10.2495/hpsu220141","DOIUrl":"https://doi.org/10.2495/hpsu220141","url":null,"abstract":"Because of its relevance in civil infrastructures, the analysis of the dynamic behaviour of concrete has increased exponentially in recent years. This is motivated by the new type of threats that have to be taken into consideration nowadays when designing these types of structures. The growing interest in the dynamic response of concrete arises from the enhancement of its mechanical properties when the material is subjected to high strain rates. In this research, the traditional Split Hopkinson Pressure Bar developed by Kolsky, with a standard compression configuration (including incident and transmitted bars) was modified into a version in which the transmission bar was removed, so that the specimen’s response is dominated by tensile stresses inside it. Spalling tests on cylindrical samples were carried out to measure the tensile strength and the fracture energy of conventional concrete. Results for strain rates ranging from 60 to 130 s –1 are presented and compared to the respective quasi-static values. As the key point of the research, two different projectile shapes (cylindrical and conical) have also been evaluated, presenting a qualitative and quantitative analysis regarding the variations in tensile stress evolution of the pulses. a deeper analysis should be done to clarify this point. From the tests, a mean value of 1.264 N/mm was obtained. Similar values of G (cid:3007) were obtained between cylindrical and conical projectiles, just a small difference in the higher strain rate produced by the cylindrical projectile. DIF parameter for the fracture energy show that even when the strain rate is kept within a narrow range, a common increasing trend can be seen.","PeriodicalId":23773,"journal":{"name":"WIT Transactions on the Built Environment","volume":"35 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76583386","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

IDENTIFICATION OF SEWAGE EXFILTRATION IN COASTAL AREAS THROUGH THE MONITORING OF DRUGS AND STIMULANT CONCENTRATIONS IN URBAN STORM DRAINS 通过监测城市雨水渠中的药物和兴奋剂浓度，确定沿海地区的污水渗漏情况

WIT Transactions on the Built Environment Pub Date : 2022-09-14 DOI: 10.2495/friar220061

S. Spengler, M. Heskett

{"title":"IDENTIFICATION OF SEWAGE EXFILTRATION IN COASTAL AREAS THROUGH THE MONITORING OF DRUGS AND STIMULANT CONCENTRATIONS IN URBAN STORM DRAINS","authors":"S. Spengler, M. Heskett","doi":"10.2495/friar220061","DOIUrl":"https://doi.org/10.2495/friar220061","url":null,"abstract":"One of the major barriers for municipalities responsible for mitigation of sewage exfiltration is locating grossly leaking sections of the sewage conveyance system in a time-, labor- and cost-efficient manner. In this study, water samples were collected from the dense network of manholes overlying the storm drain systems in the tourist area of Waikīkī and inland residential areas on the island of O‘ahu, Hawai‘i. The majority of the sewage conveyance infrastructure in this coastal area is submerged and the storm drains are routinely subject to backflow during high tide. Exfiltration of sewage from the aging conveyance system in this coastal area contaminates the surrounding shallow brackish aquifer, which then enters leaking pipe joints and cracks in the storm water conveyance system. Samples collected from the storm drains were analyzed for the presence of carbamazepine, a commonly prescribed anticonvulsant, pain relief and bipolar disorder treatment drug, which behaves as a conservative tracer in the environment (> 50 days half-life, low sorption). Samples were also analyzed for the more labile anthropogenic tracer caffeine (~4 day half-life). The higher stability of carbamazepine enables detection of this compound at greater distances from sewage release sites while caffeine serves as a better tracer for detecting recent, proximal releases of sewage, given its ephemeral nature and relatively high and ubiquitous presence. The concentration levels and spatial distribution of detection of these two anthropogenic biomarkers were successfully used to identify areas of ongoing sewage exfiltration in Waikīkī and surrounding residential communities. The variation in carbamazepine and caffeine concentrations measured in Waikīkī storm drains over a 1 year period generally correlate with daily visitor arrivals to O‘ahu.","PeriodicalId":23773,"journal":{"name":"WIT Transactions on the Built Environment","volume":"66 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84867997","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

PRESSURES–IMPACT ANALYSIS OF THE PACORA RIVER, PANAMA 巴拿马帕科拉河的压力影响分析

WIT Transactions on the Built Environment Pub Date : 2022-09-14 DOI: 10.2495/friar220101

Quiriatjaryn M. Ortega-Samaniego, Andres Fraíz, A. Dominici, A. Ramos‐Merchante, M. Pachés, I. Romero

{"title":"PRESSURES–IMPACT ANALYSIS OF THE PACORA RIVER, PANAMA","authors":"Quiriatjaryn M. Ortega-Samaniego, Andres Fraíz, A. Dominici, A. Ramos‐Merchante, M. Pachés, I. Romero","doi":"10.2495/friar220101","DOIUrl":"https://doi.org/10.2495/friar220101","url":null,"abstract":"The Pacora River is one of the priority basins of the Republic of Panama since it provides water for human consumption therefore its conservation is of great importance; the country has laws that protect the integrity of the basins from their ecological nature to that for use for economic activities. This basin has great potential not only for agricultural activities but also a buffer for population development in the urban area of the country. This study was carried out in the middle and lower upper parts of the Pacora River during the wet, dry and transitional season, the data obtained was used to calculate the water quality index and the fluvial habitat index and the elaboration of an impact–pressure matrix, in order to evaluate the levels of influence that anthropogenic activities have in the area, based on established laws regulating water quality levels and forest legislation. The results obtained indicate that the Pacora River are among the ranges of little polluted, acceptable and uncontaminated for the water quality index and for the habitat fluvial index in the range of not reaching very good, good and very good. Regarding the analysis of pressures and impacts, the values are between probable impact, checked and non-apparent impact and medium to high risk. These data indicate a shift in the use of native forest land to industrial, agricultural and urban activities.","PeriodicalId":23773,"journal":{"name":"WIT Transactions on the Built Environment","volume":"263 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76720935","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