Water Tank Structures Research Articles

Structural analysis and optimal design of a spherical thin-walled stainless steel water tank without reinforced tie ribs

A spherical thin-walled stainless steel water tank without reinforced tie ribs has been designed to address the issues of easy fracture and corrosion of the ribs, difficulty in maintenance and cleaning, and short service life exposed during the use of thin-walled stainless steel water tanks with reinforced tie ribs. Firstly, an analytical model of a flat steel thin-walled water tank without reinforced tie ribs was established and subjected to static analysis under water pressure. The deformation and stress distribution patterns of the side molded plate of the flat box were obtained. Secondly, a spherical non ribbed thin-walled stainless steel water tank structure was designed with circular cross-section under different box bulge parameters, and its mechanical response characteristics under water pressure load were analyzed. A strengthening scheme was designed for the bottom box molded plate. Once again, optimize the combination design of the box scheme and the reinforcement scheme, and analyze their static, thermodynamic, and thermal solid coupling performance. Finally, the Latin Hypercube Sampling method was used to generate experimental design samples, and a response surface approximation model of a spherical thin-walled stainless steel water tank without reinforced tie ribs was constructed. The wall thickness of the box molded plate, skeleton, and reinforcement were used as design variables, and the maximum deformation and maximum equivalent stress were used as constraints. The lightweight design was carried out with the goal of minimizing mass. The research results indicate that the design program and parameter selection method for spherical thin-walled stainless steel water tanks without reinforced tie ribs proposed in the article are efficient and feasible, and can provide technical reference and theoretical support for the layout and overall optimization design of non ribbed thin-walled stainless steel water tank structures.

A Relaxed MPC Method for Non-rigid Shell to Solid Coupling

In the finite element model of the water tank without reinforced ribs, most of the water tank structure is constructed with thin-walled parts, which are usually represented by the shell element, and for the local area with a large thickness structure, the usually solid element is used. For this area, the shell element cannot accurately simulate the stress concentration effect, while simulation with the full solid element is very time-consuming because of a large number of FE meshes. The Focus of this paper is to improve computation efficiency while ensuring the accuracy of the calculation. In this paper, a novel MPC method with a relaxed factor is proposed. Compared with the classical shell-to-solid method, the calculation results of the MPC method with relaxation factor are closer to the reference model, while the calculation time is significantly reduced by 42.1 %.

Comparative Study of Intze Type of Water Tank for Different Bracing Pattern under Wind and Seismic Load

Abstract Overhead water tank is a water storage facility supported by a tower and constructed at an elevation to provide useful storage and pressure for a water distribution system. Safety as well as working of such structures is considered as very crucial during earthquakes, since they put up for necessities like drinking water, firefighting during fire accidents, etc. Such structures should stay in operating condition even after several earthquakes. This RC overhead water tanks involves huge water mass supported on the top of tank supporting system known as staging. This investigation is basically to discover the seismic behavior of RC overhead water tanks. In this study, a FEM based model is used for finding out the nonlinear seismic performance of RC overhead water tanks with several staging variations. The staging that is different bracing patterns considered in this study in lateral and vertical direction, which relatively increases the strength and stiffness of tank in supporting system. Staad models are prepared and analyze for different seismic zones as well as for cyclonic regions and observed the parameters such as base shear, base moment and lateral displacement. The commercial software STAAD.Pro is used for structural analysis. Since the seismic response of water tank structure depends on its dynamic properties and frequency of ground motion. This seismic analysis of overhead water tank structure cannot be carried out on the basis of maximum value of ground acceleration because of nonavailability of ground acceleration data at every location. Hence for seismic analysis of overhead water tank, earthquake response spectrum analysis is widely used. While using this method, smooth design spectra is used to determine the value of displacement and forces in members at every mode of vibration. Octagonal, Radial, Cross, Alternate tie , Diagonal and X- type bracings are used to analyze the structure under all the seismic zones viz. II, III, IV & V. Also observed the behavior of tank for cyclonic region where wind load is increased by 30%. Analysed the overhead water tanks of same capacity for different bottom dome deviation angles and concluded.

전기 보일러에 적용한 비접촉 히팅 모듈의 특성에 관한 연구

This paper suggests a planar-heating element with a contactless heating module through various heating module analysis of electric boilers. This planar-heating element is made of contactless electrical heating module using a surface heaing element having an aluminum(Al) material made according to the water tank structure of the existing electric boiler. The proposed contactless planar-heating element is applied to the prototype to conduct a temperature characteristic test for each electric voltage, and the temperature characteristic test according to the flow rate. It was found that it can be applied to electric boilers, a prototype that applied the proposed contactless planar-heating module. In the future, we will apply the electrical boiler using the proposed contactless heating module to real life and apply to contactless heating module having the injection molding type material for cost reduction.

“A Comparative Study of Circular Water Tank in Two Different Loading Conditions (Seismic and Wind Load Condition) using Staad-Pro”

In this paper a comparison of the two loading combinations of a circular water tank i.e. seismic and wind load conditions have been made. The STAADPro software has been used to analyze the circular water tank structure and to compare both the loading combinations. Two similar models of a circular water tank were created, provided with the required attributes (i.e. loading conditions, zones etc.) and were analyzed in both, seismic load condition and wind load condition. The comparison of results from both the analyses revealed that, due to lower seismic zones, the effect of earthquake is slightly less than the effect of wind. It was concluded that, wind load condition should be preferred over seismic load condition while designing, because the wind load condition gives safer design in the severe conditions. This can be used for the design of a circular water tank having similar attributes.

Review on active study of water tank structure performance which is elevated & concrete shaft maintaining

This article depicts the comparative investigation for raised water tanks subjected should changing stacking backed for RC encircled structure & cement shaft structure with diverse abilities and kept in dissimilar locales for seismic. That quake historical backdrop reveals that it brought about considerably passing will people life progressively & further seismic tremor the long haul made the people to middle of the road due to wounds brought on with public utility service. Possibly in provincial alternately urban regions, the water tanks need aid raised Also structures integral & only water supply scheme such-and-such activity of post & pre quake sits tight comparative hugeness. & these movements shown that essentialness of the supporting framework will be uncompromising to raised tank concerning illustration contrasted with whatever viable kind about tank. Wounds brought on would due to inappropriate arrangement of the supporting strategy; inaccurate picking from claiming supporting system. Also these frameworks have colossal weight focused on the slender supporting method highest point consequently these frameworks were particularly powerless with strengths about level due to earthquakes. And this article speaks to the dynamic dissection of raised water tanks with admiration to those most recent may be code distributed to fluid holding structures through department about Indian principles i. E. May be 1893 (Part 2): 201. Connection of the tanks which would raise with different supporting framework abilities & seismic zones states which these elements may deliberately differ seismic direct of the tanks.

Normal Mode Analysis for Connected Plate Structure Using Efficient Mode Polynomials with Component Mode Synthesis

In the engine room and stern adjacent to the main excitation force of the ship, there are many fuel and fresh water tank structures required for ship operation which are always exposed to vibrations. Therefore, it is necessary to review the anti-vibration design to prevent such vibration problems at the design stage, and for this reason, although commercial finite element analysis (FEA) programs are widely used, approximate analysis methods are still developed and used because of the limited time until modeling and analysis results are obtained. Until now, only known elastic boundary conditions have been used in many studies using approximate analysis methods used to calculate natural vibrations for beams or plates. However, many local structures, such as tank edges and equipment foundations, consist of connected structures and it is very difficult to find suitable elastic boundary conditions. Vibration analysis of many local structures in ships, such as tanks and supports for equipment, can be simplified by breaking them up into smaller subsystems which are related through geometrical conditions and natural conditions at junctions. In this study, polynomials for simple support and fixed support were proposed to represent each subsystem and a polynomial to be applied to the plate constituting the tank was proposed by combining them. Until now, there have been many studies on single beams or single plates for approximate analysis. However, there was no research on this to the extent that no reference material could be found for the connected structure. The proposed method has been applied to tanks which are bounded by bulkhead and a deck. The results of this study shows good agreements with those obtained by the FEA Software (Patran/Nastran).

Innovative Experimentation on Hollow Cylindrical Shells of Reinforced Concrete under Axial Compressive Load

Reinforced concrete elevated water tanks supported on shaft type staging system are popularly constructed now a days for storage of water for water supply schemes. If slip form is used for casting of the shaft staging, the water towers generally require lesser time for construction. Elevated water tanks are top heavy structure especially in the tank full condition. It is often a critical question in structural design that what should be the proper structural model adopted for design of such class of structure. Should the shaft be designed as a hollow cylindrical column subjected to axial compression or is it essentially a R.C. cylindrical shell subjected to membrane forces under axial compression. To better understand it is proposed to cast such R.C. shells and after water curing for 28 days shall be subjected to axial compressive load in a compressive strength testing machine. The failure pattern of the shells shall be observed critically to get a proper understanding of behavior of such R.C shaft supported elevated water tank structures.

Self-healing and leakage performance of cracks in the wall of a reinforced concrete water tank

A reinforced concrete water tank is a typical functional liquid storage structure and cracks are the greatest threat to the liquid storage structure. Tanks are readily cracked due to seismic activity, thereby leading to the leakage of the stored liquid and a loss of function. In order to study the effect of cracks on liquid storage tanks, self-healing and leakage tests for bending cracks and through cracks in the walls of a reinforced concrete water tank were conducted. Material performance tests were also performed. The self-healing performance of bending cracks in a lentic environment and through cracks in a lotic environment were tested, thereby the self-healing width of bending micro-cracks in the lentic environment in the short term were determined. The through cracks had the capacity for self-healing in the lotic environment was found. The leakage characteristics of the bending cracks and through cracks were tested with the actual water head on the crack. The effects on liquid leakage of the width of bending cracks, the depth of the compression zone, and the acting head were determined. The relationships between the leakage rate and time with the height of the water head were analyzed. Based on the tests, the relationships between the crack characteristics and self-healing as well as the leakage were obtained. Thereby the references for water tank structure design and grading earthquake damage were provided.

Study on Analysis and Design in Reinforcement Structure Joints of Water Tank Structure for Safety Human life

A water tank is used to store water to surge over the daily requirement. In the construction of concrete structure for the storage of water and other liquids the imperviousness of concrete is most essential. The permeability of any uniform and thoroughly compacted concrete of given mix proportions is mainly dependent on water cement ratio. The increase in water cement ratio results in increase in the permeability. The decrease in water cement ratio will therefore be desirable to decrease the permeability, but very much reduced water cement ratio may cause compact ion difficulties and prove to be harmful also. Design of liquid holding structure has to be based on the anticipation of cracking in the concrete having regard to its tensile strength. Cracks can be prevented by avoiding the use of thick timber shuttering which prevent the easy escape of heat of hydrate ion from the concrete mass the risk of cracking can also be minimized by reducing the restraints on free expansion or contraction of the structure.

Structural Analysis for Design Improvement of Stainless 5,000ton Rectangular Water Tank Structures

The finite element analysis of large sized rectangular water tank structures made of stainless steel materials is carried out for various combined load cases. The combined load cases for a large size of 5,000ton are further determined using the specification(KS B 6283) established from the Korean Standards Association. For the better numerical efficiency, the rectangular panels are modelled using the ANSYS program. The numerical results obtained for different load cases show as follows. In order to resist the snow load, it takes the influence of the gap than the size of the column. Also, in order to resist the water pressure, it shall increase the thickness of the wall. But, increasing the thickness of the wall is considerably less economical. Therefore, the angle with big thickness should be placed right next to the wall.

Finite Element Stress Analysis of Large Sized Rectangular Water Tank Structures Made of Stainless Steel Materials

The finite element stress analysis of large sized rectangular water tank structures made of stainless steel materials is carried out for various combined load cases. The combined load cases for a large size of 5,000ton are further determined using the specification(KS B6283) established from the Korean Standards Association. The changed water capacity due to the size of reservoirs could be heavily dependent for evaluating seismic effects, especially for large reservoirs. For the better numerical efficiency, the rectangular panels are modelled using the ANSYS ADPL module. The numerical results obtained for different load cases mainly show the effect of the interactions between the different load combination and other various parameters, for example, the water capacity, and different stainless steel materials. The structural performance for various load combinations is also evaluated.

On the Seismic Performance of Elevated Water Tanks and their Control Using TLDs

The post-earthquake function of elevated water tank structures so as respond to the civil water requirements is of extreme significance. These structures are, however, extremely vulnerable to seismic conditions and there has been substantial damage/failure of several such structures during major earthquakes. A review of the damage and performance of some elevated water tanks subjected to earthquakes is presented in this paper. An investigation is also made on the seismic vibration control of elevated water tank structures by using Tuned Liquid Dampers (TLDs). A frequency domain formulation for the transfer function of the elevated water tank with attached TLDs is developed. Numerical studies on a reinforced concrete elevated water tank with shaft type support are carried out. The effect of detuning on the performance of the TLDs due to the change in the structural frequencies resulting from the fluctuating water level in the water tank is also examined. Results indicate that it is possible to design a fairly robust and effective TLD system for the seismic vibration mitigation of the considered elevated water tank.

Capybara (Hydrochoerus hydrochaeris) behaviour and welfare: implications for successful farming practices

AbstractCapybara (Hydrochoerus hydrochaeris) farming in Latin American countries was hampered at the outset by limited knowledge of species behaviour and inappropriate husbandry protocols, which resulted in low reproductive rates, lethal adult fights and consequent reduced well-being. As the peculiarities of capybara social behaviour are still ignored by many species’ breeders, both in commercial or research centres, we aim here to provide a review of successful experiences in Brazil by evaluating a number of social behaviour issues that are directly associated with the species’ welfare. We highlight special points on group composition and facilities needed, such as water tank and corral-trap structures, which may affect capybara health, productivity, and animal welfare. It has been shown that trying to form new aggregates by mixing adult or sub-adult animals obtained from different groups does not work. Conversely, we did not find a difference in the frequency with which mothers from the same group nurse their own young or those of other females. This knowledge may lead to successful trials for female adoption when necessary. In conclusion, capybara welfare is strongly linked to cohesion among animals. Additionally, assessment of vocal emissions is discussed as a potential, non-invasive measure to evaluate improvement in capybara handling procedures.

The effect of seasonally frozen soil on stochastic response of elevated water tank under random excitation

Significant seismic events have occurred around the world during winter months in regions where cold temperatures cause ground freezing. Current seismic design practice does not address the effects of cold temperatures in the seasonally frozen areas. Since many elevated water tank structures in cold regions are located in seismic active zones, determining the effect of seasonally frozen soil on the stochastic response of elevated water tank structures subjected to random seismic excitation is an important structural consideration. A three dimensional finite element model, which considers viscous boundaries, was built up to obtain the stochastic seismic behavior of an elevated water tank–fluid–soil interaction system for frozen soil condition. For this model, the power spectral density function represents random ground motion applied to each support point of the three dimensional finite element model of the elevated water tank–fluid–soil interaction system. Numerical results show that the soil temperature affects the seismic response of the elevated water tank; whereas the variation in the thickness of the frozen soil causes insignificant changes on the response. In addition, the effect of the variation in water tank’s fullness on the stochastic response of the coupled system is investigated in the study. As a result, the seasonal frost changes the foundation soil stiffness and may impact seismic behavior of the water tank.

A Review on Numerical Simulation of Pile Caps in Large-Scale Structures

Cap plays a transitional role in the structure. It is an important part to ensure the effective pass of load between the upper structure and the foundation. In the bridge, water tank, ocean platforms, oil tank and other large-scale structures, the force mechanism and force mode about cap are more and more valued by researchers. The research method about large cap structure mainly includes theoretical research, experimental research, numerical simulation and other aspects. This article summarizes the domestic research status, reviews and compares the caps’ numerical simulation methods and analyzes the advantages and disadvantages of different models. Finally, some problems are proposed for further research, which can provide references for engineering design and study.

In Situ Performance Testing of Deteriorating Water Tanks for Durability Assessment

Reports of failure of existing concrete structures due to a lack of durability, rather than a deficiency in structural strength, has made concrete technologists, engineers, and researchers focus research on the parameters influencing durability performance with respect to time. Systematic performance monitoring, with respect to chosen durability parameters of existing concrete structures, will decide the direction of future research in this area. Inferences based on laboratory simulations and testing need to be confirmed by in situ field measurements and studies. In situ condition rating and performance monitoring surveys have been conducted by many researchers, scientists, and professional associations, and reported in literature. Inferences of few such studies are summarized and discussed. Deterioration of concrete structures constructed in recent times is observed at relatively faster rates, and has been mainly attributed to cracking. Cracking is associated with the use of faster-hydrating portland cements with increased fineness and the tricalcium silicate (C3S) content to support the high speed of modern construction. In the present research, a case study of deteriorated water tank structures situated in the semitropical region of India is presented. Some selected parameters—such as concrete cover, carbonation depth, chloride concentration, compressive strength, etc. which influence long term durability of structures—have been measured.

In-Service Durability Performance of Water Tanks

With an alarmingly increased rate of deterioration in reinforced concrete structures due to durability performance, efforts are being made to quantify in situ performance. Performance is a function of time and it is related to degradation and the parameters influencing it. Although state-of-the-art modeling of various deterioration mechanisms is available in the literature, evaluation of the influence of various deterioration mechanisms that decrease performance with time is difficult. However, in situ condition documentation, survey, and assessment of deteriorated structures reflect the resultant deterioration process and also helps in validation of experimental and theoretical methods of performance evaluation. In this research, a systematic in situ condition documentation, survey, and assessment of water tank structures has been done based on an empirical damage scale similar to that suggested in the literature and a bilinear graphical deterioration model for such water retaining structures in a semitropical region like India is presented on the basis of case studies.

접수 탱크 구조물의 진동특성에 관한 연구 - 종횡비 변화와 압력분포 -

접수 탱크 구조물의 진동특성에 관한 연구 - 종횡비 변화와 압력분포 -

접수탱크구조의 진동특성에 관한 연구

접수탱크구조의 진동특성에 관한 연구