Design Of Walls Research Articles

Physics-informed models of domain wall dynamics as a route for autonomous domain wall design via reinforcement learning

Prompted by limited available data, we explore data-aggregation strategies for material datasets, aiming to boost machine learning performance. Our findings suggest that intuitive aggregation schemes are ineffective in enhancing predictive accuracy.

Effect of the axial compression ratio on the seismic behavior of resilient concrete walls with concealed column stirrups

Abstract The axial compression ratio is one of the important factors affecting the seismic performance of reinforced concrete (RC) walls. Thus, the axial compression ratio is critical in the seismic design of RC walls. In addition to the axial compression ratio, the other significant experimental parameter is the stirrup form of the boundary elements. To study the effect of the axial compression ratio and the stirrup form on the seismic behavior of ductile RC walls reinforced by prestressed concrete strands, four full-scale concrete walls were constructed and subjected to reversed cyclic lateral loading while experiencing constant axial compression, with axial load ratios set at 0.17 and 0.26. The considered stirrup forms of the boundary elements are circular and compound, respectively. All specimens exhibit significant drift-hardening capability with a small residual drift and a small crack width. The ultimate capacity, ductility, stiffness and attenuation process, hysteretic characteristics, energy dissipation capacity, residual deformation, and maximum and residual crack width of the shear walls are compared and analyzed. The experimental results and comparisons between the two groups of shear walls with different axial compression ratios and stirrup forms of concealed columns are presented. The characteristics of the envelope curve are also analyzed, and a simplified bilinear envelope curve model is proposed to better fit the test results.

TINY HOUSE IN THE DESERT: A study in indoor comfort using moveable insulation and thermal storage

A tiny house for seasonal rangers was designed for the extreme climate and diurnal temperature fluctuations of Joshua Tree National Park. The challenging climate conditions resulted in an extensive investigation of the building envelope to act as a passive thermal storage system to naturally cool and heat the house. The north wall was designed as a “cold battery,” which uses a dynamic internal and external insulation system with a high-mass concrete wall to achieve coolth absorption at night as part of a thermal management system and to achieve indoor thermal comfort under extreme desert climates. A combination of opening an exterior insulation system at night to absorb coolth, closing the exterior insulation system when the temperature rises, and opening the interior insulation system to release coolth was attempted. The goal was to achieve a comfortable indoor temperature without the use of HVAC systems. Several software programs were tested for their capabilities to simulate time lag in concrete and thermal storage including Opaque and IES VE. The design of the north wall was carried out for different conditions such as different modulating profiles, locations and thicknesses of insulation, and the data were collected and analyzed again. IES VE was able to successfully simulate the effects of moving interior and exterior insulation twice a day on different sides of a concrete wall. In consideration of the special occupancy type, the expansion of the comfort zone for seasonal rangers is achieved by the specification of a comfortable temperature range from 65°F to 85°F. In a standard year, consisting of 8,760 hours, simulations were conducted on the entire residence, primarily during the months when seasonal rangers were present, to investigate thermal comfort conditions. These assessments encompassed various aspects, including ventilation (2,941 comfort hours), the north wall (4,653 comfort hours), the base model (2,883 comfort hours), and enhancements to the south wall (5,543 comfort hours) and the east and west glazed facade (6,137 comfort hours). The culmination of these findings significantly contributed to an enhanced overall comfort experience within the tiny house design, specifically tailored to accommodate the needs of seasonal rangers at Joshua Tree National Park. Natural ventilation proved to be a good strategy.

Study on Miura Folding Technology and Its Application in Sound Insultation

Based on the wings of dragonflies, Japanese astrophysicist Koryo Miura invented a new folding technology called Miura folding. The core principles of Miura folding include symmetry, periodicity, and compactness. The structure of Miura folding is arranged alternately by multiple parallel creases, which can remain stable when unfolding and folding. The Miura folding has the advantages of compactness, speed, structural stability, mathematical controllability, and multi-field application. Compared with traditional methods, the Miura folding provides more efficient, flexible, and more controllable solutions for a variety of application scenarios, from space technology to practical tools in daily life. This article reviews the origin and advantages of Miura folding and discusses its applications, focusing on the design and innovation of Miura folding sound insulation walls. The progress in design, the challenges related to the control of sound insulation, and the sound insulation of Miura folding are discussed. In addition, this article also discusses the application of Miura folding in other fields, the application of Miura folding technology in the era of globalization, and the prospect of future Miura folding technology in the emerging technology field. This article may offer a reference for the development of folding technology.

Dynamic analysis of MSE wall subjected to surface vibration loading

Abstract Extensively used Mechanically Stabilized Earth (MSE) walls in Rail Transportation System (RTS) are vulnerable to surface vibrations generated by moving vehicles. Hence, it is necessary to consider the effects of surface vibrations during the design of MSE walls for RTS. Steel-reinforced panel-type MSE walls are shown to perform well during vibration loading, but costly steel materials have led to greater reliance on affordable and readily available geosynthetics for reinforcement. Limited research exists on the behavior of panel-type MSE walls with geosynthetics considering RTS-induced vibrations frequencies. Thus, this study employs Finite Element software PLAXIS 3D to simulate the impact of surface vibration frequencies on panel-type MSE walls. The qualitative study encompasses two reinforcement cases (geogrids and steel strips) of 4 m MSE wall height and four harmonic loading frequencies representing RTS-induced surface vibrations for simulation. The dynamic responses of MSE wall are presented in terms of lateral wall displacements and lateral earth pressure distributions. Furthermore, the distributions of tensile strain and the identification of potential slip surface locations are presented. The findings indicated that MSE wall and reinforcement responses are governed by RTS-induced vibrations and fundamental frequency of backfill soil. This highlights the need for consideration of both the fundamental frequency of the backfill soil and RTS-induced vibrations in the design of MSE walls.

Study on seismic behavior of prefabricated shear walls with steel double tube connections

The joints are crucial for influencing the overall mechanical performance of precast shear wall constructions under seismic actions. The existing joint connections are complex and not efficient enough. To maximize the potential of prefabricated structures, this study proposed innovative prefabricated shear walls with steel double tube connections. Two pseudo-static tests were conducted to investigate the influence of axial compression ratio on the seismic behavior of the innovative shear walls. The failure modes were all bending failures, and it had been discovered that increasing the axial compression ratio can improve the carrying capacity and energy dissipation capacity. Seven models with different axial pressure ratios were established to conduct nonlinear finite element analysis. The result showed that as the axial compression ratios raised, the carrying capacity and stiffness of the models increased, but the decreasing trend of force–displacement curves were also more distinct. Therefore the recommended axial pressure ratio of the models did not exceed 0.4. Finally, the calculation method of the loading capacity of novel shear walls was proposed, which provided the basis for the design of innovative shear walls.

Fuzzy logic based prediction of retaining wall stability

In geotechnical engineering, retaining walls are widely employed to solve the problem of supporting horizontal loads occurring between two different soil levels. In the traditional retaining wall design, stability checks continue until a safe design is obtained according to selected wall dimensions and soil properties. This design method is a process that is time-consuming and based on trial and error. In this study, the stability control of the retaining wall, which is a complex engineering design, has been carried out with fuzzy logic methods. Adaptive network-based fuzzy inference systems (ANFISs) including Grid Partition (ANFIS-GP) and Substructive Clustering (ANFIS-SC) have been utilized as fuzzy logic methods. The sliding stability criterion of the cantilever retaining wall has been obtained by performing 1024 retaining wall designs which are created using different wall dimensions. Ninety percent and ten percent of the 1024 sliding safety factor values acquired through numerical analyses were respectively allocated to the training and testing phases. The prediction performances of the methods have been evaluated by considering the Root Mean Square Error (RMSE), Mean Absolute Error (MAE), and Coefficient of Determination (R²) obtained for the sliding safety factors during the training and testing stages. Upon juxtaposing the actual and anticipated sliding safety factors for a dataset comprising 1024 observations, it has become evident that the ANFIS-SC methodology outperforms the ANFIS-GP approach in terms of predictive accuracy. Furthermore, this analysis culminated in the determination that the application of fuzzy logic methods stands as an efficacious and dependable means for checking the stability criteria of retaining walls.

Methodology development for assessing the reliability and quality of engineering protection to ensure the stability of the motorways earth bed

The analysis of regulatory documentation compliance in the reliability assessment field of engineering protection systems with the current scientific and technical level has been carried out. The analysis of the adopted technical regulations for the retaining walls design has revealed a significant drawback — the lack of a consistent algorithm of actions for transport works facilities diagnostics. In the framework of the current research a methodology for assessing the retaining walls operational reliability and landslide protection works on landslide highway areas has been developed. The article summarizes the main deformations of engineering protection structures, allowing to determine the retaining structures technical condition located in the territories prone to landslide processes, and also presents the concept of the standard technical solutions album for repair and walls restoration. The analysis of the main problems arising in the design, construction and operation of retaining wall structures and highlighting it from the view point of ensuring the erected structures required reliability and durability will optimize the work process and reduce the number of emergency failures and losses due to their occurrence, as well as through the classification and bringing the documentation into a

Investigation of Different Filling Wall Design in Steel Structures with Linear and Nonlinear Earthquake Analysis Methods

Ülkemiz, önemli fay hatlarının üzerinde bulunmaktadır. Çeşitli parametreler açısından yapısal davranışın irdelenmesi yapıların deprem güvenliği için önemlidir. Sıkça tercih edilen taşıyıcı sistem türlerinden olan çelik yapıların davranışı üzerinde dolgu duvar etkisi bu çalışmada incelenmiştir. Uygulamada, dolgu duvarlar genellikle düşey yük olarak analizlere dahil edilirken, modele katılmadıkları için özellikle yatay yük altında yapısal davranış üzerindeki etkileri göz ardı edilmektedir. Bilindiği üzere; dolgu duvarların sayısal modele katılıp katılmamasının yapıların davranışı üzerinde olan etkisinin araştırılması yapı güvenliği açısından da önemli bir durum arz etmektedir. Çalışmada incelenen sayısal modeller SAP2000 programında üç boyutlu olarak analiz edilmiştir. Eşdeğer deprem yükü yöntemi ile deprem etkisi altında yapısal davranış incelenmiş ve artırımsal eşdeğer deprem yükü yöntemi ile yapı performansı araştırılmıştır. Analizlerden elde edilen sonuçlar ışığında sayısal modelinde dolgu duvarların basınç çubuğu olarak dikkate alındığı durumda, dolgu duvarların yalnızca düşey yük olarak dikkate alındığı duruma göre periyot değerlerinin arttığı, tepe noktası deplasmanlarının azaldığı görülmüştür. Diğer taraftan, aynı incelemede basınç çubuğu olarak dolgu duvarın modele katıldığı durumda taban kesme kuvvetinin arttığı ve daha az deplasman ile plastik mafsallaşma noktasına ulaşıldığı sonucuna varılmıştır.

Enhancing heat transfer in microchannels: A systematic evaluation of crescent-like fin and wall geometries with secondary flow

Recent developments in additive manufacturing processes, coupled with the demands of modern microelectronics, have spurred research in heat sinks at the micro-scale. The present study introduces microchannel designs resembling crescent-like walls and fins inside a coolant-based heat sink to enhance its thermal performance. Three different microchannel designs, namely the crescent-like fin design (CF design), the crescent-like wall design (CW design), and the crescent-like wall design with secondary flow (CWSF design) have been proposed and evaluated for their ability to transfer heat while maintaining a low pressure drop penalty. Furthermore, these geometries were tested with different inlet–outlet configurations. The paper investigates flow profile, pressure drop, and temperature profiles for a wide range of flow rates and explores certain hydrodynamic phenomena, such as the Coanda effect and vortex formation generated by the network of convex and concave surfaces that induce flow disruption, thus increasing the potential for enhanced thermal performance. Velocity and temperature maldistribution analyses have also been included to compare the stress distribution around the microchannel walls, highlighting the relative potential for structural failure. The findings suggest that incorporating secondary flow passages inside the crescent-like walls would result in a 28–51% reduction in pressure drop, indicating the potential to meet the thermal management needs of modern microchips. The main objective of the paper is to study how varying the attributes of crescent-like geometries affects the flow profile and thermal performance of a heat sink. The study aligns with the requirements of modern microchips, such as the 13th Gen Intel® Core™ processor, and serves as a guideline for the manufacturing of microchannel heat sinks with crescent-like morphologies.

Rotordynamic characteristics of a novel labyrinth seal with partition walls and helical groove teeth

To improve the stability of the conventional labyrinth seal (LS), in this paper, four novel fully partitioned helically labyrinth seals (FPHGLS) were designed and they were in comparison with one FPPGLS. The influences of the preswirl ratio and the helical groove pitch on the leakage flow and rotordynamic characteristics were numerically investigated, using the transient computational fluid dynamics (CFD) method based on the multi-frequency elliptical whirling orbit model. The accuracy and availability of the present transient numerical method were demonstrated based on the experiment data. The results show that the partition walls design can significantly increase the direct damping and cross-coupling stiffness for labyrinth seals and the helical teeth design can significantly decrease the cross-coupling stiffness and tangential force. When the helical groove pitch is equal to the seal length, the leakage nearly remains unchanged. Compared to the baseline design (LS), the FPPGLS and the FPHGLS have similar and significantly larger direct stiffness and direct damping. The two designs possess positive direct stiffness throughout the frequency range. The FPPGLS and FPHGLS possess significantly higher direct damping (∼323.7% larger than LS). But the FPPGLS possesses the largest cross-coupling stiffness among three seals at two preswirl ratios. From preswirl ratio = 0.13–0.84, the cross-coupling stiffness of the FPHGLS decreases by 53.4-310.1% compared with the FPPGLS. Increasing the helical groove pitch increases both direct stiffness and direct damping and reduces cross-coupling stiffness, but it also leads to greater leakage losses. In general, the novel FPHGLS whose helical groove pitch is equal to seal length possesses superior rotordynamic characteristics and similar leakage characteristic. This work provides the reference of the seal design and safety operation for the turbomachinery.

A Damage Index for Assessing Seismic-Resistant Designs of Masonry Wall Buildings Reinforced with X-Bracing Concrete Frames

In this paper, a suitable damage index is demonstrated to assess the seismic-resistant design of masonry wall buildings reinforced with double x-bracing concrete frames. As a criterion indicative of the damage level that might occur after an earthquake, the damage index can be calculated by using analytic results, by using the Park–Ang formula on masonry wall buildings reinforced with concrete structures, and by adjusting the index values in accordance with the results of the analysed models. The data used in this study are collected from the results of four-storey concrete structures with masonry walls under cyclical lateral forces. To simulate the masonry walls’ structural behaviours for damage assessment, x-bracings placed as crosses on each bracing are used to support the compressive strength. Then, the analysis results are used to assess the damage that occurs to the masonry wall building structure by considering deformation and energy decay; additionally, a suitable damage index is calculated for each damage level. The damage index can be considered in the seismic-resistant design of masonry walls reinforced with x-bracing concrete frames.

Effect of modelling the infill wall as a strut element on the structure behaviour

This study investigates the effect of modelling the infill walls as a strut element on the building behaviour of a 5-story reinforced concrete frame building with and without modelling infill walls as a strut element. The study was conducted using finite element analysis. Five different building heights (15 m, 16.5 m, 17.5 m, 18.5 m, and 19.5 m) were considered as changing in the first story height. The results showed that the modelling of infill walls as strut element significantly increased the stiffness of the building, reducing the time period of building, and increasing the base shear force. The increase in stiffness was more clear in model with height 19.5 m model, also the modelling of infill walls as strut element were more effective in reducing the lateral displacement of the building at the higher floors.The results of this study suggests that the modelling infill walls as strut element can be effectively used to improve the seismic performance of reinforced concrete frame buildings, also provides valuable information for the design of infill walls and the effect of modelling the infill walls in calculating the soft story and torsion irregularities according to the Turkish earthquake code 2018 (TEC18) (Turkish Earthquake Code Mart, 2018).

Sectional strength design of a double-skin truss-reinforced composite shear wall

The double-skin truss-reinforced composite shear wall is an innovative element which comprises two steel plates, core concrete, concrete-filled steel tubes (CFSTs), which act as boundary members, and steel truss connectors. Truss connectors decrease the out-of-plane deformation that affects the steel plates, and due to the resultant connection and constraint effects, the truss connectors enhance the bearing capacity of the wall. This paper briefly introduces the quasi-static test of five full-scale rectangular double-skin truss-reinforced composite shear wall specimens. The specimen exhibited shear compression failure with an aspect ratio of 2.0, and flexure shear failure occurred when the aspect ratio exceeded 2.0. Based on the analysis of actual stress state of the steel web and actual working performance of the infilled concrete, the shear strength and flexure strength design formulas of double-skin truss-reinforced composite shear wall were established. Comparison results with 26 specimens demonstrate that the design formulas exhibit remarkable accuracy, as most errors are within 20 % and 25 %, respectively. Which provide a preliminary sectional strength design proposal for the double-skin truss-reinforced composite shear wall.

Numerical Study on Welding Structure of Connecting Fin Used in Thermal Power Plant

The background of deep peak-shaving poses demanding requirements for the performance of metal components in thermal power plants. The cracking of the connecting fins on the side wall of the flue seriously endangers the safe operation of the system. Herein, welding simulations were carried out using the finite element method to understand the cracking process of the connecting fins. By changing the welding process and fin size, their effect on stress and deformation was explored. The results showed that increasing the welding rate would decrease the flexural deformation of the flue-side wall. Additionally, the yield range of the connecting fin depended more on width than thickness, and increased with increasing width. As for the relationship between fin size and flexural deformation, the maximum deformation decreased with the increase in thickness, while it first decreased and then increased with increasing width. Overall, the post-welding stress and deformation of the boiler flue side wall exhibited more sensitivity to the fin width compared with the fin thickness and welding rate. This article clarifies the stress distribution status of the connecting fins in the flue side wall under different welding conditions, providing a basis for analyzing its cracking phenomenon, and further providing theoretical guidance for optimizing the structural parameter design of the side wall.

Minimum cost, stability constrained preform optimization for hybrid manufacturing

This paper describes a new mathematical framework for optimum preform design in hybrid manufacturing, where additive manufacturing is combined with machining. The framework minimizes the combined cost for deposition and machining, while respecting the constraint imposed by machining stability (i.e., machining parameters that produce chatter are rejected). A case study is presented where a thin wall design is parameterized to describe the overbuilt deposition geometry. A grid of candidate solutions is selected to calculate cost and the stability limit considering both the part and tool dynamics. The minimum cost option is deposited and machined to demonstrate the approach.

Comparative aesthetic assessment of machine learning and human judgment for building wall designs

Machine learning models can potentially provide alternative options in the field of architecture as aesthetic judgment tools, owing to their high capacity and data-driven environments. If a machine learning model can produce aesthetic evaluation results similar to those of humans, the process may be highly promising for further applications in architectural decision-making. In this study, we propose a series of interconnected workflows for a rigorous comparison, including data collection, machine learning, parametric designs, robotic fabrication, and human surveys, to test the compatibility between human judgment and machine learning models in the aesthetic assessment of architectural objects on the same design objects. We observed a wide gap between the aesthetic judgments of the two groups. We discuss certain drawbacks and current limitations to improve the vulnerability of the study process and conclude by providing an outlook for the subsequent direction of a similar study.

Experimental study and mechanism analysis of out-of-plane seismic performance of reinforced concrete shear walls

Compared with the in-plane seismic performance, the out-of-plane seismic performance of reinforced concrete shear walls is weak and usually neglected, which leads to an inadequate study of the out-of-plane damage mechanism of shear walls and a lack of clear protective measures. In order to compare the similarities and differences in seismic performance of reinforced concrete shear walls when subjected to in-plane and out-of-plane loads in different directions and to clarify the key influencing factors, low cyclic loading tests were carried out on typical shear wall specimens in both in-plane and out-of-plane directions. The moment-curvature simulations of shear wall sections in both in-plane and out-of-plane directions are analyzed. The effects of parameters such as axial pressure ratio, wall thickness, height to width ratio and concrete grade on in-plane and out-of-plane seismic performance were analyzed at the member level in combination with finite element variable parameter analysis; at the structural system level, the time history analysis of 2 frame shear wall structures for single seismic action and main-aftershock sequence is established, and the structural damage is evaluated through the maximum story drift and rotation. The results reveal that the out-of-plane seismic performance of shear walls is significantly weaker than their in-plane seismic performance, with a difference of 1/20∼1/15 times in bearing capacity, where wall thickness and aspect ratio are the main parameters affecting in-plane and out-of-plane seismic performance; when the shear walls in the structure are subjected to seismic action in the out-of-plane direction, their out-of-plane direction will undergo large deformation and damage will occur easily, especially in the Single directional wall with less structure. The out-of-plane nonlinear analysis of the cross-section can be performed more accurately and quickly by using the new principal structure model proposed in this manuscript and some traditional principal structures. In the seismic design of shear walls, both in-plane and out-of-plane seismic performance should be ensured, and the wall thickness and height to width ratio of shear walls should be reasonably controlled.

Numerical study on thermal performance of a building design integrating two passive Trombe walls

ABSTRACT This paper deals with a numerical simulation of the transient thermal behaviour of Trombe walls. The temperature fields and velocity distributions are investigated in different components of a test room, in the climate of Lille- France, during two different seasons in order to provide a thorough comprehension of the potential of the Passive Trombe wall. The governing equations are solved by the Finite Volume Method using the CFD software scSTREAM V2020. The numerical results agree well with the available experimental data. The results indicated that the temperature values at the upper vents were always higher than those retrieved from the lower vents forming an air circulation in the space which promotes a comfortable indoor air temperature. Besides, other parameters such as the thickness of Trombe wall, vents dimensions and air gap thickness, are studied to inquire their influence on the Trombe wall’s performance. It is found that the Trombe wall should be constructed with middle thickness with smaller air gaps to enhance thermal comfort in a building. This investigation can be a good reference for Trombe wall design and a valuable insight into the development of a high-efficiency solar air heating system.

Experimental investigation on seismic performance of cold-formed steel strap-braced stud walls under lateral cyclic and vertical loading

Cold-formed steel (CFS) construction offers several benefits over traditional construction, including being lightweight, sustainable, recyclable, quick to build, insect and rot-resistant, and suitable for computer-aided design and manufacture. Despite extensive research on CFS elements, there are still gaps in our understanding of the behaviour of CFS structural systems, particularly their response to severe earthquake events. This experimental program aims to provide a better understanding on the seismic behaviour of strap-braced stud-walls as a lateral force resisting system for residential medium-rise buildings. An innovative test rig is developed that is capable of applying a constant vertical load during lateral cyclic testing, replicating the loading conditions expected during an earthquake event in such cases. For the first time, seven full-scale tests are conducted on CFS walls under vertical and horizontal loading using standard sections in New Zealand. The vertical capacity, lateral stiffness, ultimate strength, ductility, and failure mechanisms of the specimens are investigated. Subsequently, a modified detailing is suggested, which allows CFS walls to exhibit considerably better seismic behaviour compared to the systems with conventional detailing. It is shown that by adopting the modified detailing, CFS walls exhibit an ideal elastic-plastic curve with negligible degradation in successive cycles and a high ductility factor exceeding 5. The results of this study should prove useful for more efficient design of CFS strap-braced stud walls for mid-rise buildings.