Tank Wall Research Articles

Trade-Offs between Avoidance of Noxious Electric Shock and Avoidance of Bright Light in Shore Crabs Are Consistent with Predictions of Pain.

The suggestion that decapod crustaceans might experience pain has been dismissed by some authors who claim decapods only respond to noxious stimuli by nociceptive reflexes. Because reflexes do not require complex neuronal processing, but pain does, demonstrating reflex responses to noxious stimuli would not support the case for pain. Here, we report an experiment in which shore crabs are repeatedly placed in a light area (20 trials), but the animals can avoid the light by moving to a dark shelter. However, some crabs received an electric shock of 6 or 12 volts each time they entered the shelter. Those receiving either level of shock swiftly reduced their use of shelters and remained in the light. However, the magnitude of shelter avoidance was influenced by the brightness of the arena and the intensity of the shock. Shelter use was subsequently reduced to a greater extent if the shock level was high and the light intensity low. That is, crabs traded their avoidance of shock for their avoidance of bright light. Further, these animals showed avoidance learning and demonstrated activities suggesting anxiety, such as contact with the tank wall in the light area and increased latency to enter shelters when making the decision to enter the shelter if they had received shock in earlier trials. These results fulfil three key behavioural criteria for pain and, thus, are consistent with the idea that decapods can experience pain.

Verification of ultimate limit state of reinforced concrete walls of rectangular tanks with use “sandwich model” according to abendment of Eurocode

In the paper the calculations of reinforcement area of exemplary reinforced concrete squat silo for coal are presented. The results of classical calculation and calculation executed with use of ”sandwich model” are compared. The last one is recommended in the amendment of EC2-1-1 code. The calculations are preceded with compilation of standard recommendations concerning the dimensioning of concrete membranes, shells and plates

Optimal estimation of MC parameter in SAE J2601 hydrogen refuelling protocol based on modified formula and artificial neural networks

The MC method was officially released in SAE J2601 protocol in 2016 to refuel light-duty hydrogen fuel cell vehicles quickly and safely. For the non-communication MC method, the pressure target for controlling the end of filling is calculated based on the formula of the final hydrogen temperature, which contains a key parameter, MC. SAE has proposed two formulas to estimate the MC parameter. This article proposes a modified formula and artificial neural networks (ANN) model for MC parameter. To generate simulated data for fitting the modified formula and training the ANN model, a hydrogen filling model (0D1D) with a zero-dimensional gas and a one-dimensional tank wall is established and thoroughly verified. In establishing the ANN model, Latin hypercube sampling (LHS) is used to sample independent variables randomly, and genetic algorithms (GA) are used to optimize the initial weights and biases of the ANN. The Sobol sensitivity analysis is used to determine the importance of various initial conditions on the MC parameter. Research shows that the final fueling time and initial pressure have a greater impact on the MC parameter, while the ambient and precooling temperatures have little impact. The modified formula of the MC parameter improves R2 from the original 0.76073 to 0.98132 when fitting the MC simulated data. In situations of short filling time, the modified formula and ANN models of the MC parameter reduce the relative error between the 0D1D model by 13.8 % − 58.8 % and 16.6 % − 82.3 %, respectively, thus improving the calculation accuracy of the final hydrogen temperature and ending pressure target. Moreover, the ANN model can predict the MC parameter during the whole fueling process, while the MC formula utilizes the fixed value when the fueling time is less than 30 s. This work has positive significance for improving refuelling protocol.

Tank Cleaning Process Optimization For Loading Tanks MT Bauhinia Guna Cargo Change

Suboptimal implementation of tank cleaning will produce suboptimal results and can affect loading failure. These less than optimal results are influenced by several things. Tank Cleaning is a tank cleaning carried out on a tanker which serves to reduce the risk of damage to the cargo. Wall wash test is a tank cleanliness test for chemical tankers after completing tank cleaning. In the loading process, chemical tankers must prepare their loading tanks in accordance with the correct procedures. In every process of preparing this tank must always pay attention to the standards that have been determined from the surveyor or based on IMO (International Maritime Organization). When the Chemical ship will load, the ship's tank will be checked by the cargo surveyor, if there is dirt or residual cargo before the ship can be declared a failure in the tank cleaning process and as a result the ship will be ordered out of the Jetty, ordered to re-clean. This causes company losses because there will be delays in the loading and discharging process of the ship and the company gets complaints from the charter party. The method used to carry out the research is descriptive qualitative. Cutting the time for tank cleaning can result in poor tank cleaning results, poor quality materials also result in less than optimal results, and equipment that lacks maintenance will result in less than optimal tool performance. When the Chemical ship will load, the ship's tank will be checked by the cargo surveyor, if there is dirt or residual cargo before the ship can be declared a failure in the tank cleaning process and the ship will be ordered out of the Jetty and ordered to re-clean. This causes losses to the company because there will be delays in the loading and discharging process of the ship and the company can get complaints from the charter party. The success or failure of tank cleaning and wall wash tests depends on the discipline of the crew, adequate tools and materials, and procedures that are carried out properly.

A Review of Two Decades of In Situ Conservation Powered by Public Aquaria

The European Union of Aquarium Curators (EUAC) boasts a membership of 150 dedicated individuals, standing as a vital cornerstone within the European public aquarium community. Since 2004, the EUAC Conservation Fund has granted over a quarter of a million euros to approximately 50 conservation projects spanning the globe. These initiatives, diverse in nature and scale, have yielded tangible impacts on local populations and their focal species. This paper delves into the outcomes of these conservation endeavors and proposes enhancements to ensure that the funding is unequivocally channeled towards conservation efforts. One resounding observation gleaned from the array of projects spotlighted in this study is the profound community engagement that emerges, irrespective of the final project outcomes. These endeavors serve as a catalyst for local communities, shedding light on subjects that would otherwise remain shrouded in obscurity. Furthermore, the EUAC-backed projects illuminate the expansive reach of public aquarium initiatives, transcending the confines of acrylic tank walls and institutional boundaries to resonate globally, heightening local awareness about the imperative to safeguard biodiversity. These findings underscore a prospective trajectory for both the EUAC and the public aquaria it comprises: an intensified advocacy and collaboration with legislative bodies to fortify in situ conservation measures. In essence, it is imperative that the public comprehends the pivotal role played by aquaria in preserving a multitude of species and acknowledges that their visits directly contribute to funding projects aimed at safeguarding species within their natural habitats.

New type of cavitation instability with peculiar frequency characteristic in liquid rocket inducer

In a liquid rocket turbopump with low pressure and thin wall tanks, cavitation inevitably occurs at the inducer which is installed at the inlet of the turbopump. The cavities at each blade oscillate periodically, and the turbopump sometimes becomes unstable, called cavitation instability. Rotating cavitation is one of the common types of cavitation instability, in which the cavities at each inducer blade oscillate respectively and appear to propagate from blade to blade. However, the new type of cavitation instability which does not follow the conventional principle has been observed in our experiment with an inducer. Converting the frequency in the inertial frame to that in the rotational frame and organizing it in the cavitation number, it was found that the frequency of unsteady cavitation increases as the cavitation number decreases, and this is the peculiar point of this instability. Additionally, during the cavitation instability, a few numbers of backflow vortex cavities were observed and moved sub-synchronously from blade to blade. In addition, the tip leakage vortex cavitation on each blade also propagates like sub-synchronous rotating cavitation but in different propagation speed from that of the backflow vortex cavities. As a result, it was supposed that the new instability is one of the types of sub-synchronous rotating cavitation related to backflow vortex cavitation, tip leakage vortex cavitation, and interaction between cavity propagation and inducer blade.

Insulation of feed water tank in arrangement of transportable boiler plant with direct-flow steam boiler

A transportable boiler plant is used to provide consumers with steam of high energy characteristics, while saving costs for the construction of stationary boiler houses. A transportable boiler plant can be placed in the conditions of the Far North on an oilfield site. It is therefore necessary to organize reliable and safe operation of the boiler house, consisting of a steam direct-flow boiler of the coil type, a feed pump, a feed water tank and other auxiliary elements of the thermal circuit. One of the important elements in the thermal circuit is the feed water tank, in which water accumulates after chemical purification. It is where the water is also heated, increasing the efficiency of the boiler. Methods for calculating the diameters of main steam pipelines and feed water pipelines are described. The theoretical foundations of the operation of the feed water tank, its use in thermal power plants, combined heat and power plants, district industrial and heating boilers using various thermal arrangements of the above-mentioned enterprises are considered. The operation of the feed water tank in the thermal circuit of a steam unit is discussed. A thermal circuit of an industrial boiler house has been designed to generate saturated steam for consumers using direct-flow steam boilers of the coil type. The diameters of the inlet and outlet pipelines of the storage tank are calculated. The effective thickness of thermal insulation required to minimize heat losses during operation of a transportable boiler plant has been determined. Modeling of the design of the feed water tank and heat losses through its surface is carried out. A 3D model of the designed tank is presented, as well as heat losses through the surface of the tank walls when using a thermal insulation material. The importance of using thermal insulation of various tanks for storing feed water, petroleum products, hydrocarbons and other various media is noted.

Comparison of Empty and Oil-Filled Transformer Tank Mode Shapes Using Experimental and FEM Modal Analysis

In this paper, the mode shapes of an empty and oil-filled transformer experimental model tank are obtained using 3D finite element method (FEM) modal analysis. For verification of the FEM analysis results, experimental modal analysis (EMA) is carried out in both cases using appropriate impact hammers and accelerometers. Simulated and measured results are visualized and compared for mode shapes in a frequency range of interest for both empty and oil-filled tanks. In order to avoid overly stiff FEM models of transformer tanks, the welded joint modeling technique is presented and analyzed in detail. For an oil-filled tank, the most accurate results are calculated in the model where the welded joint is modeled as half the tank wall’s thickness. In that case, the mean absolute error for the given ten-mode shapes is 1.7 Hz. Also, mesh sensitivity analysis is performed. It is concluded that a 10 mm maximum element size is an optimal solid (3D) mesh. However, shell mesh can be used to reduce computing requirements.

Numerical investigation on oil leakage and migration from the accidental hole of tank wall in oil terminal of pipeline transportation system

As a crucial component of the oil transportation system, the oil terminal (or oil tank farm) may often pose some serious threats and damage to the ecological environment and production safety for the oil leakage. An effective emergency management strategy is particularly significant, involving the accurate assessment of leakage time, oil migration path, volume distribution, etc. Therefore, the volume of fluid (VOF) and liquid phase leakage model were applied to investigate the migration and distribution characteristic after the accidental hole occurs in the tank wall, and influence factors including height and diameter of the hole were considered in our study. Results show that the lower the leaking hole position is, the faster the horizontal injection rate of the leakage hole, the increase of the accumulation area of the oil on the ground, and the difference in the overall pressure value at the leakage hole is nearly four times. Under different leakage diameters, the oil spill is symmetrical. The larger the leakage diameter, the higher the amount of oil leakage and the initial leakage speed, the maximum speed is 1.5 times the minimum speed, causing harm to safety and environmental pollution. These results can quickly locate the leakage location of the tank and provide valuable references for emergency management of the oil pipeline transportation system.

Seismic Response Analysis of Rectangular Reinforced Concrete Tank Constructed on Loess Soil

Introduction: Liquid storage tanks are an essential container structure widely used in various industries. In earthquake disasters, liquid storage tanks cause not only direct disasters but also induce secondary severe disasters, such as fires, explosions, nuclear leaks, and human and animal poisoning. The latest research on seismic analysis of structures showed that soils with different stiffness can affect the seismic response characteristics of surface structures, and various irregular topographies can also alter the degree of seismic-induced damage to surface structures. Studying the seismic response of liquid storage tanks can mitigate the risk of earthquake damage to these vital structures. Methods: This study used finite element simulations. Three sizes of liquid storage tanks with different aspect ratios were selected, including the squat, square, and slender tanks. Three conditions were considered for the tanks' liquid: empty, half-filled, and fully filled. Two types of topographies were considered, including flat and step-like slope topography with an inclination angle of 116.6°. Nine natural earthquake records were used for seismic analysis and divided into three categories: high-frequency, medium-frequency, and low-frequency. Established finite element models were validated through comparison with the results of other studies. The dynamic time history analysis was carried out for each finite element model. The tank's base shear forces, the normal stress in the tank wall, the shear stress in the tank bottom, and the maximum displacement of the tank wall were measured and compared. Results: The step-like slope topography and loess soil significantly amplified the seismic response of the liquid storage tank. Moreover, as the liquid height and the tanks’ aspect ratio increased, the seismic damage intensity also increased. The seismic response of the liquid storage tank was generally more sensitive to low-frequency and medium-frequency seismic records. The Eurocode 8’s equation underestimated tanks’ base shear when located on a step-like slope topography. Conclusion: The obtained results demonstrated the significant effect of irregular topography and loess soil on the seismic response of liquid storage tanks. Therefore, it was concluded that they should be considered when liquid storage tanks are designed for seismic actions.

Improvement of MC method in SAE J2601 hydrogen refuelling protocol using dual-zone dual-temperature model

The MC method has been published in the SAE J2601 refuelling protocol to safely and quickly refuel hydrogen fuel cell vehicles. This article adopts a dual-zone dual-temperature model that distinguishes the hydrogen temperature from the tank wall temperature to replace the dual-zone single-temperature model of the original MC method. A model (0D1D) of lumped parameter gas (0D) and one-dimensional tank wall (1D) is established simultaneously to verify the modified MC method and generate simulation data. A modified formula to the original MC method for calculating final hydrogen temperature is derived, which contains a correction factor K. The formula and coefficients of the correction factor K are determined by fitting the simulated data from the 0D1D model. The correction factor K is expressed in a piecewise function. The formulas of K are relatively complicated, so another simpler correction factor k is derived, which is a linear function. Research shows that the modified MC method extends its applicability to situations of refuelling times <30 s, while the original MC method is unsuitable. In the conditions set in this article of ambient temperature 0 to 40 °C, precooling temperature −40 to −20 °C and initial pressure 2 to 60 MPa, the modified MC method reduces the errors of final hydrogen temperature between the 0D1D model by 2 to 7 °C compared to the original one, thus improving the calculation accuracy of the pressure target and reaching a more accurate state of charge. In a word, the modified MC method improves the accuracy of refuelling control and has positive significance for the operational safety of hydrogen refuelling stations and the driver's refuelling experience.

Negative stiffness and inerter-based dampers: Novel seismic response control approach for base isolated liquid storage tanks

Liquid storage tanks (LSTs) have become indispensable to civil engineering infrastructure. LSTs are used not only for storing harmless fluids but also explosive, toxic, and hazardous substances. Thus, the ability of LSTs to withstand significant seismic activity without damage is a major worry. Strong pulse-type characteristics in near fault (NF) type of ground motions have shown significant base and sloshing displacements for a commonly adopted structural control measure: base isolation (BI). The current study introduces negative stiffness and inerter dampers (NSIDs) as supplemental response control measures to LSTs with BI (BILSTs). Conventional supplemental damping applications in the isolation system are helpful in displacement reduction at the isolator level, but the upper structure response gets severely affected. This study presents NSIDs, characterised by the damping magnification effect, as supplemental dampers to BILSTs. The continuous liquid mass within the tank is represented by discrete lumped masses referred to as sloshing, impulsive, and rigid mass. The stiffness constants of these lumped masses are derived by considering the tank wall and stored liquid physical parameters. The optimal supplemental damping parameters are deduced by developing contour plots describing the sloshing and base displacement response reduction (mitigation) ratios. Through analytical studies conducted using real earthquake records, it has been demonstrated that appropriately designed Negative Stiffness and Inerter Devices (NSIDs) yield enhanced performance for Base Isolated Liquid Storage Tanks (BILSTs). These optimised combinations of NSIDs effectively mitigate isolator displacement, base shear, lumped sloshing mass displacement, and sloshing mass height in response to both near-field (NF) and far-field (FF) base excitations.

3D Change Detection Method for Exterior Wall of LNG Storage Tank Supported by Multi‐Source Spatial Data

AbstractChange detection methods for measuring deformation of the LNG storage tank's exterior wall cannot meet the requirements for extensive and comprehensive deformation analysis. The method proposed in this paper uses multi‐source spatial data to detect the deformation of the LNG storage tank's exterior wall. Exterior wall data collected simultaneously by terrestrial and airborne laser scanners, as well as close‐range and oblique photogrammetry, are pre‐processed separately and then registered to the global point clouds. The deformation state of exterior wall is represented by a thorough assessment approach that takes into account four change indices. The results suggest that the registration precision of global point clouds is 6 mm. The global ovality of the LNG storage tank is 0.053%, with a tilt change of 2.58° and a deviation of 27 mm in the direction of the azimuth of 321.98°, an average value of 0.07 mm for depression and protrusion deformation, and a surface flatness of 21.3 mm. In this case, the flatness is greater than the variation threshold of the standard specification, indicating that the tank may have structural uneven settlement or other deformation problems. The attraction of the proposed method resides in its capacity to efficiently and accurately obtain spatial positioning and color information of the LNG storage tank's exterior wall, thereby providing a robust foundation for precise judgments regarding the deformation state.

Thermocline Storage Tank with Concrete Filler

A thermal storage of 2500 kWh is designed, built and installed at the site of the experimental solar tower of Themis in Targasonne (France) within the POLYPHEM project (H2020 program, Ref N. 764048). The thermal energy storage (TES) consists of a thermocline tank with solid filler and thermal oil as heat transfer fluid. Tank walls, filler bricks and foundations are made of concrete. This new concept introduces some challenges that have been addresed during the construction and commissioning of the TES system. In this paper, authors present the main issues and solutions adopted for the tank design and construction.

Computational heat transfer analysis of liquid food in a heat exchanger with varying stirrer settings in a nonclassical continuum framework

Rapid heat diffusion and stirring of food in channels and tanks for more desirable and safely regulated food delivery is of particular interest in food industry. In the present article, we investigate heat diffusion in a heat exchanger with varying stirrer settings in a nonclassical framework. Interestingly, the liquid food flows in all previous investigations are modeled using the classical continuous paradigm. Therefore, the purpose of this article is to offer a mathematical model that uses a nonclassical continuum framework to mimic the behavior of liquid food flows. This is influenced by the fact that during the stirring process, food particle microrotations affect the heat diffusion phenomenon, necessitating consideration of this in the modeling aspect of such studies. This non-Newtonian physical process is modeled based on the well-established theory of Cosserat continuum. The mathematical model presented here is taking into consideration a newly established constitutive relation by the author for the strain-based viscosity models in non-Newtonian mechanics. The applied constitutive relation incorporates the microrotational effects into the current rheology of rate-dependent viscosity model as a result of the kinematics at the macroscopic level. It offers a more practical method for examining the heat diffusion process in a heat exchanger. To the best of the author’s knowledge, this approach is first of its kind in analyzing heat diffusion process within non-Newtonian mechanics. The presented strain-based viscosity model is described in the form of PDEs along with prescribed boundary conditions. An in-house code is developed based on finite element method. The code is implemented using FreeFEM++. Liquid food flow in a heating process is analyzed numerically for heat transfer characteristics with varying Cosserat number and other physical aspects. Simulations are performed in a channel connecting a tank with different stirrer settings. Computed results are analyzed in a limiting case for accuracy and a strong agreement is achieved with the available solutions from the literature. Some interesting features of the liquid food flow and heat transfer are presented and discussed. It is observed that when liquid food particles rotate faster, the temperature difference between the walls also increases. The temperature difference between the top and bottom walls of the liquid food tank increases with faster speed of stirrers. Rise in the Cosserat number results in a dispersed vortices throughout the liquid food tank. The temperature differential between the liquid food tank’s top and bottom walls rises as a result of an increase in the microrotational motions of the food particles. Moreover, the microrotational motion of the liquid food particles rises with an increase in Cosserat number, enabling effective particle mixing.

Numerical research on the thermal characteristics and mechanical properties of a molten-salt single tank storage system

Single-tank thermal storage systems are an effective solution for enhancing the stability and continuity of solar power plants. The thermal characteristics and safety of the cycling process are essential indicators of single-tank performance. In this study, an integrated model of the finite volume method (FVM) and finite element method (FEM) is established for a molten-salt single tank system with a composite wall, and the effects of operating parameters and structural parameters on the cyclic dynamic thermal and mechanical characteristics are investigated. Our findings indicate that increasing the inlet flow rate reduces the heat storage capacity and increases thermal efficiency, while increasing the equivalent stress on the tank wall. However, increasing the inlet/outlet temperature difference enhances the thermal efficiency and the wall equivalent stress and reduces the heat storage capacity. Additionally, a reduction in the solid particle diameters improves the dynamic thermal properties of a single tank, and the thermal efficiency increases from 92.1 % to 94.1 % when the particle diameter decreases from 0.05 m to 0.01 m. In a composite wall structure, increasing the firebrick thickness improves the thermal efficiency and mechanical properties of the tank, while increasing the steel shell thickness improves the stress concentration on the tank wall. Therefore, to improve the thermal efficiency of a single tank and guarantee its security, the inlet flow rate and inlet/outlet temperature differences should be controlled within a certain range. Furthermore, the diameters of solid particles should be reduced, the thickness of the firebrick should be increased and the thickness of the steel shell layer should be controlled within a certain range.

Research on temperature rise calculation and hot spot temperature inversion method for oil immersed transformer based on magnetic - thermal - fluid

The hot spot temperature of oil-immersed transformer winding is an important factor affecting the aging of material insulation. In this paper, a magnetic field simulation model is established based on the electrical and structural parameters of the oil-immersed transformer, and the loss distribution characteristics of each wall of the transformer core, winding and fuel tank are accurately calculated by using the finite element simulation software. The simulation model of transformer fluid- thermal field is established, the simulation results of transformer thermal field are obtained, and the temperature distribution of oil-immersed transformer core and winding and the flow velocity around it are obtained. According to the simulation results of thermal field, the characteristic temperature measuring points with strong correlation between tank wall and winding temperature were determined. The inversion models of tank wall and winding hot spot temperature were established by using the support vector regression and BP neural network algorithm respectively by central composite design method. The results show that the correlation coefficient of support vector regression algorithm in predicting winding hot spot temperature reaches 0.98, and the relative error between the model predicted value and the real value is less than 8%, which is more accurate than BP neural network. The above research provides the theoretical basis and technical support for real-time monitoring of oil-immersed transformer winding hot spot temperature.

Research on temperature rise characteristics and hot spot temperature inversion method of oil-immersed transformer based on coupling of magnetic-fluid-thermal field

The hot spot temperature is an important factor affecting the operation state and insulation life of oil-immersed transformer. It is of great value to carry out multi-physical field coupling simulation research on magnetic-fluid-thermal field of oil-immersed transformer and accurately calculate and predict the hot spot temperature of transformer for transformer service life evaluation. In this paper, the oil immersed transformer is taken as the research object, and five characteristic parameters of the hysteresis model are obtained by using PSO optimization algorithm according to the experimental magnetic characteristics data of the core material and the classical J-A hysteresis model, A 3D simulation model of magnetic-fluid-thermal field is established based on the electrical and structural parameters of the oil-immersed transformer. Combined with the magnetic characteristics of the core material, the thermal field and the surrounding fluid distribution of the transformer core and winding are obtained by two-way coupling method. On this basis, in order to accurately reflect the correlation between the hot spot temperature of the transformer winding and the temperature of the oil tank wall, the selection position of the characteristic temperature point of the transformer tank wall is determined by streamline analysis method, and the hot spot temperature of the oil-immersed transformer is retrieved by support vector machine method. The results show that the prediction accuracy of the hot spot temperature reaches 0.998, and the inversion method has a high enough accuracy. It provides theoretical basis and technical support for real-time monitoring of hot spot temperature in oil-immersed transformer windings.

Behavior of Base-Isolated Liquid Storage Tanks with Viscous Dampers under Historical Earthquakes Considering Superstructure Flexibility

Liquid storage tanks (LSTs) can be efficiently protected from far-fault earthquakes by base-isolation. However, large isolation system and sloshing displacements may threaten the tank’s safety under near-fault earthquakes. Although the application of supplemental viscous dampers (VDs) at the base-isolation systems of LSTs located in near-fault areas may help, it may also increase superstructure demands under far-fault earthquakes. In addition to the characteristics of the earthquake, the isolation system and the superstructure properties may affect the success of base-isolated LSTs with supplemental VDs. Therefore, a numerical investigation is conducted in this study in order to determine the influence of the supplemental viscous damping ratio, the isolation system period, the tank wall flexibility, and the tank slenderness ratio on the seismic responses of base-isolated cylindrical steel LSTs with supplemental VDs including the base displacement, the sloshing displacement, and the normalized isolation system shear force under both near-fault and far-fault historical earthquake records. The tank is modeled by single-degree-of-freedom systems representing different modes on a common isolation basemat and the nonlinear dynamic analyses are carried out in 3D-BASIS-ME software. Findings show that while supplemental damping is required especially when LSTs with long-period isolation systems are subjected to large magnitude near-fault earthquakes, it may also cause amplifications in the sloshing displacement and isolation system shear force demands in case of far-fault earthquakes. Furthermore, it is determined that the influence of tank flexibility on both the superstructure and the isolation system responses is negligibly small while the tank slenderness ratio may have considerable effects.

Damage Behavior of Multilayer Axisymmetric Shells Obtained by the FDM Method

This research rigorously explores the additive synthesis of structural components, focusing on unraveling the challenges and defect mechanisms intrinsic to the fused deposition modeling (FDM) process. Leveraging a comprehensive literature review and employing theoretical modeling and finite element analysis using ANSYS software, the study meticulously investigates the behavior of multilayer axisymmetric shells under varying internal pressure conditions. Critical parameters are identified, and the impact of design factors, including material properties, geometric parameters, and internal pressure, is quantitatively assessed using a rich digital dataset. In a series of model experiments, the study reveals specific numerical results that underscore the progressive nature of damage development in FDM-produced multilayer axisymmetric shells. Notably, under increasing internal pressure, stresses on the tank’s inner walls reach up to 27.5 MPa, emphasizing the critical importance of considering material properties in the design phase. The research also uncovers that the thickness of tank walls, while significant in resulting stresses, does not markedly impact the damage development mechanism. However, it places a premium on selecting rational parameters for the honeycomb system, including shell thickness, honeycomb height, honeycomb wall thickness, and honeycomb cell size, to minimize stress concentrations and enhance structural integrity. The inclusion of honeycomb structures in the tank design, as evidenced by specific results, provides enhanced thermal insulation properties. The research demonstrates that this design feature helps localize damage and mitigates the formation of significant trunk cracks, particularly along generative cracks.