Reticulated Shell Structure Research Articles

Seismic performance improvement of a three-dimensional isolated spherical reticulated shell structure using pseudo-negative-stiffness magnetorheological dampers

Seismic performance improvement of a three-dimensional isolated spherical reticulated shell structure using pseudo-negative-stiffness magnetorheological dampers

Seismic performance of pentagonal type aluminum alloy suspen-dome structure with large opening

Prestressing technology is an effective way to enhance the mechanical properties of space structures. In view of this, a new pentagonal type aluminum alloy suspen-dome structure with large opening is proposed in this paper by introducing the lower cable support system into the aluminium alloy single-layer reticulated shell structure. The seismic performance of this new structure is investigated using time-procedure analysis. Firstly, the effects of rise-span ratio, thickness-span ratio, prestressing level, horizontal radius factor for lower chord nodes and roof loading on the free vibration characteristics of the structure with different supporting stiffness are investigated. The distributions of internal forces and displacements of members of overall structure considering lower support and roof structure only are analyzed. Subsequently, the dynamic response of the structure under seismic combinations of different dimensions and directions is investigated, and reasonable combinations that should be considered for simplified analyses are derived. Furthermore, seismic internal force coefficients are introduced to assess the degree of seismic effects on various types of members. On this basis, parametric analysis of the seismic performance of the structural performance is conducted and quantitative assessment of the sensitivity of the parameters is carried out. Additionally, the free vibration characteristics and dynamic performance of steel and aluminium suspen-dome are compared. The results show that considering the supporting structure weakens the structural stiffness while increasing the structural dynamic response; reasonable values of key parameters in the seismic design of the structure are obtained; and the rise-span ratio and thickness-span ratio are important influencing factors of the seismic performance of the structure. Besides, the internal forces of members in aluminium alloy suspen-dome are less affected by seismic effects than those in steel suspen-dome, and the new structure has good seismic performance.

Generation and evaluation of unimaginable three-dimensional structural joints using generative adversarial networks

Compared to the increasingly programmable and automated structural analysis methods, the current joint design suffers from long design time, poor quality and a low degree of automation. Developing an efficient and intelligent method to generate structurally novel and high-performing joints has become an urgent task. This paper combines artificial intelligence, topology optimization and reverse engineering techniques to develop a method named HD-JointGEN, and elaborates the idea and implementation steps of this method through an actual engineering example of a single-layer reticulated shell structure. The joints generated in batch by HD-JointGEN are analyzed and evaluated, revealing that the selected representative joint can reduce self-weight by 29.55%, maximum displacement by 0.99%, and maximum equivalent stress by 1.28% compared to the topology optimization joint. HD-JointGEN not only automatically generates a variety of innovative and previously unimaginable joints but also offers design solutions with superior force performances. It leads the research on intelligent generative design of the connection in complex three-dimensional structures and has broad application prospects.

Shaking Table Tests and Numerical Analysis Conducted on an Aluminum Alloy Single-Layer Spherical Reticulated Shell with Fully Welded Connections

Aluminum alloy offers the advantages of being lightweight, high in strength, corrosion-resistant, and easy to process. It has a promising application prospect in large-span space structures, with its primary application form being single-layer reticulated shells. In this study, shaking table tests were conducted on a 1/25 scale aluminum alloy single-layer spherical reticulated shell structure. A finite element (FE) model of the reticulated shell structure was established in Ansys. Compared with the experimental results, the deviation in natural frequency, acceleration amplitude, and displacement amplitude was less than 20%, confirming the validity of the model. An extensive analysis of the various rise–span ratios and connection constraints of a single-layer spherical reticulated shell structure was carried out using the proposed FE model. The experimental and simulation results showed that as the rise–span ratio of the aluminum alloy reticulated shell increases, the natural frequency of the reticulated shell structure also increases while the dynamic performance decreases. The connection of the circumferential members changes from a rigid connection to a hinged connection. The natural frequency of the reticulated shell structure is reduced by about 40% while the acceleration and displacement response values are decreased by approximately 15%.

Progressive Collapse Resistance Analysis of Plate-member Composite Reticulated Shell Structure

Progressive Collapse Resistance Analysis of Plate-member Composite Reticulated Shell Structure

Crashworthiness of AAG joints with a foam aluminum layer gusset plate

The gusset joint is the most widely used joint system in an aluminum alloy single-layer reticulated shell structure; it plays a vital role in the spatial grid structure. In this paper, the effects of different thicknesses of aluminum alloy gusset plates on the dynamic response and failure modes of aluminum alloy gusset (AAG) joints were studied by impact tests of three specimens. The test results show that the failure modes of AAG joints are a slight depression of the gusset plate, the local buckling of members, the local distortional buckling of members, and tearing of the lower flange and a web of members. The AAG joint inclines along the direction of the failed member and collapses. The finite element model of the AAG joint was established using ANSYS software. The stress, displacement, and deformation modes in the test and numerical simulation results were compared and analyzed, and the rationality of the numerical simulation results was verified. Based on the failure mode of the specimens, a design method for improving the impact resistance of AAG joints with aluminum foam layer gusset plate (AFLGP) is proposed. The numerical simulation results show that an AAG joint with an AFLGP effectively reduces the maximum peak value of impact loads through the deformation of the aluminum foam. In the elastic and elastic-plastic stages, AAG joint with AFLGP had better impact resistance, and the energy absorbed by its rods was 25.44% ∼ 30.36% lower than that of AAG joints alone. Finally, the influence of the thickness of the AFLGP on the impact force and energy absorption of the AAG joint was studied. The aluminum foam gusset layer plate is approximately twice as thick as the aluminum alloy gusset plate had the best protection effect on the AAG joint.

A comprehensive study on seismic dynamic responses of stochastic structures using sparse grid-based polynomial chaos expansion

The seismic response is a critical aspect of structural engineering, as it directly influences the design and safety evaluation of such systems. Structural seismic response becomes more complicated when unavoidable uncertainties in the structure are considered. Therefore, solving and analyzing the stochastic dynamic response of structures efficiently and accurately is of great significance. Various uncertainty quantification methods such as the stochastic finite element method, Monte Carlo method, and polynomial chaos expansion method have made significant progress in this field. However, these methods do not provide a comprehensive study of the seismic response of stochastic structures and efficiency problems rapidly emerge as the number of random variables increases. This paper delivers a comprehensive study of the seismic dynamic response of space truss and reticulated shell structure considering uncertainties in material properties, geometry, and loading. To this end, the finite element model of the structure was first modeled and the deterministic solutions were obtained. Then, polynomial surrogates are modeled for the natural frequency, mode participation factor, mode superposition response, and transient response of the structure under stochastic uncertainties. The sparse grid technique is used to select sparse quadrature points, which overcomes the curse of dimensionality caused by full grid integration. The results demonstrate that the sparse grid-based polynomial chaos expansion is more efficient. Uncertainty quantification reveals the uncertainty of modal analysis, response spectrum analysis, and transient response analysis of space truss and reticulated shell under seismic excitation. In summary, this study provides valuable insights and an efficient and accurate uncertainty quantification tool for the seismic dynamic analysis of stochastic structures, ultimately contributing to safer and more robust structural designs.

Dynamic Responses of Single-Layer Reticulated Shells under Oblique Impact Loading

This paper focuses on the response of reticulated shell structures under oblique impact loads, with a departure from the traditional emphasis on vertical impact loads. These structures are typically utilised in large-span spaces such as iconic buildings and large venues. The study begins by establishing a numerical simulation method for reticulated shell structures subjected to oblique impact loads, which is then validated against existing experimental results. Building on this verified method, the research delves into the effects of varying impactor mass, velocity, and initial kinetic energy on the reticulated shell structure under oblique impacts, as well as the influence of different oblique impact angles. The study extensively examines the failure modes of the structure, node displacements in the structure, and variations in member stress under different impactor parameters. It further investigates how these parameters influence the maximum impact bearing capacity, impact duration, energy dissipation capability, and response forms of the structures, analyzing the reasons behind these effects. The findings offer valuable insights for further research and practical engineering design of reticulated shell structures.

Numerical investigations of seismic responses of non-isolated and isolated double-layer cylindrical reticulated shells with substructure

The seismic performance of the spatial double-layer cylindrical reticulated shell was numerically simulated using the finite element program ABAQUS, based on the data obtained from the shaking table test. And the simulated natural frequency, acceleration response, and stress response of the model are compared with the test data. The results show that the numerical analysis of spatial double-layer cylindrical reticulated shells considering lower support can accurately simulate the test results. Due to the significant impact of model vibration and other flaws on the structural reaction and the data collecting system, the precision of the test under small-seismic conditions is lower than that under large-seismic conditions. Consequently, a numerical simulation is employed to study the collapse performance of the test model. The results show that the numerical simulation can accurately investigate the failure and collapse behavior of the structure. Additionally, a numerical simulation is conducted on the shaking table test of a spatial double-layer reticulated shell structure incorporating the new three-dimensional isolation bearing. The numerical simulation results are in good agreement with the test results. However, due to the complex mechanical properties of the new three-dimensional isolation bearing, the simulation accuracy of the isolation model is less than that of the non-isolation model. Finally, the numerical simulation results show that the isolation bearing can significantly improve the seismic performance of the structure and greatly increase the safety of this kind of structure by changing the first three modes of the structure and avoiding the predominant period. The analysis conclusion of this paper will provide a good reference for the seismic isolation research and engineering practice of spatial double-layer cylindrical reticulated shell structure.

Structural static reanalysis using flexibility disassembly perturbation and system reduction

Rapid static reanalysis technology is an important tool commonly used in structural optimization design and reliability analysis. The existing static reanalysis methods are not efficient enough in solving high-rank large modification problems. To overcome this drawback, this paper proposes a new method for structural static reanalysis based on flexibility disassembly perturbation and system reduction. Firstly, a generalized flexibility disassembly perturbation technique is developed to directly compute the flexibility matrix of the modified structure. Subsequently, a new system reduction method is proposed to quickly approximate the exact solution of the modified static displacement. Even for the global large modification problem, the proposed method only requires two basis vectors to obtain very accurate calculation results. Two numerical models of statically indeterminate structures are used to verify the effectiveness and progressiveness of the method. The results show that the proposed reanalysis method has higher computational accuracy than the existing combined approximation (CA) and preconditioned conjugate gradient (PCG) methods, especially for the high-rank large modification case. A steel reticulated shell structure is further used to illustrate the application of the proposed reanalysis method in structural reliability analysis. It can be found that the proposed method significantly saves the calculation time of structural reliability analysis.

Form-finding for Free-form Reticulated Shell Structure Considering Structural Performance and Regularization of Node Connection Patterns

In this study, we propose a form-finding method for the free-formed reticulated shell structure, considering both structural performance and regularization of node connection patterns. The coordinates of the nodes of the reticulated shells are represented on the non-uniform rational B-spline (NURBS) surface. According to the principal curvature, the clustering classifies the node connection patterns into specified groups. Multi-objective optimization is performed to minimize the strain energy and maximum deviation in clusters. A multi-objective genetic algorithm is used to solve the optimization problem. The mechanical properties of the optimal solution obtained in a numerical example are discussed to confirm the effectiveness of the proposed method.

On the Similarity Relationship between the Structural-Steel Prototype and the 304-Stainless-Steel Dynamic Scale Model

Due to the size limitations of shaking tables, dynamic scale models of large-span space structures for engineering have small cross-sections and thin wall thicknesses. It is difficult to use the structural steels commonly used in prototypes to make dynamic scale models. In this paper, 304 stainless steel is proposed for making the scale model, and the similarity relationship between the structural-steel prototype and the 304-stainless-steel dynamic scale model was studied. Firstly, a uniaxial test was conducted to study the elastic modulus similarity and the yielding stress similarity. The test results demonstrated that the elastic modulus similarity ratio was 1:1, and the stress similarity ratios of the 304 stainless steel and the three typical structural steels were 1:1 (Q235 steel), 1:1.5 (Q355 steel) and 1:1.8 (Q420 steel). Then, the similarities of other variables were derived using the dimensional analysis method. In the end, a numerical analysis was conducted to verify the similarity relationship between the structural-steel prototype and the 304-stainless-steel dynamic scale model. In the numerical analysis, a single-layer spherical reticulated shell structure and a dynamic scale model with a length similarity ratio of 1:20 were established by using the ABAQUS 2021 software, and the node displacement, the element internal force and natural vibration characteristics were analyzed. The results show that standard deviations of the displacements, the internal forces and the natural vibration frequencies between the prototype and the scale model were within 5%. It turns out that the proposed similarity between the structural-steel prototype and the 304-stainless-steel dynamic scale model was applicable in the elastic stage. The findings provide a reference for designing a dynamic scale model of large-span space structures for engineering by using 304 stainless steel.

Evaluation of isolation performance of, reticulated shell structures with curvature-consistent frictional pendulum isolation system through shaking table tests

In this study, we investigated the isolation effect of a curvature-consistent frictional pendulum bearing isolation system (CC-FPB-IS) on a long-span spatial structure. Considering a typical spherical reticulated shell in a long-span spatial structure as the research object, we conducted shaking table tests on a scaled reticulated shell structure equipped with fixed hinge bearings and CC-FPBs. In addition, a refined finite element simulation method was established to analyze to the seismic impact on an actual reticulated shell structure with isolation layers under different isolation conditions. The variations in the isolation effect on the dynamic responses under horizontal unidirectional, vertical, and three-dimensional ground motions were compared. The results indicated that the isolation layer comprising the CC-FPB can notably reduce the horizontal dynamic response of a reticulated shell structure under horizontal seismic action while retaining its elastic state during rare earthquakes. With increasing loading amplitude, the isolation rate of the long-span spatial structure increased and gradually reached the optimal value. However, the proposed CC-FPB-IS did not effectively reduce the dynamic response of the vertical component, and the isolation rate was relatively small. When subjected to a three-dimensional earthquake, the structure exhibited an isolation effect because of the coupling of earthquake components in different directions. Thus, the CC-FPB-IS has notable effects on the dynamic response of the overall structure.

Theoretical analysis and model manufacturing of innovative mortise and tenon hollow spherical joint

One of the main challenges for free-form surface reticulated shell structure recently is the development of a new joint that is able to implement complex-shaped curvature and fulfill the required loading capacity, whilst also meeting various important requirements such as convenient on-site assembly and suitability for connecting members with various cross-sectional forms. This article draws inspiration from the construction idea of Chinese traditional mortise and tenon structure and proposes a new type of mortise and tenon hollow spherical joint. To investigate the joint’s mechanical performance, the detailed numerical models of 29 mortise and tenon hollow spherical joints with different size parameters are established by SolidWorks and Ansys, and the effects of the hollow spherical wall thickness, tooth width, tooth spacing, tooth height and tenon face width on the joint bearing performance are analyzed. The joint failure modes under bending limit states are discussed, and the calculation formulas for the initial and elastic-plastic stage rotational stiffness are derived. The results show that the joint initial rotational stiffness is increased by 34.45%, 4.69%, 4.29%, and 3.25%, respectively, after the parameter optimization analysis of the hollow spherical wall thickness, tooth width, tooth spacing and tenon face width. The mortise and tenon hollow spherical joint has good mechanical performance, and possesses the advantages of simple and beautiful appearance, fast construction speed and high positioning accuracy. Finally, a reduced-scale model of the mortise and tenon hollow spherical joint is manufactured using 3D printing technology to visually showcase its external feature and validate its assembly characteristic.

Numerical investigation on stability of reticulated shell structures composed of built-up plate members

A novel type of reticulated shell structure composed of built-up plate members has been proposed based on its benefits in efficiency and precision of fabrication, as well as convenience of storage and transportation. This study aims to investigate the stability behavior of such structures by conducting numerical simulation analysis. The configuration of the structure is illustrated at first. Then, a validated numerical model is presented for parametric studies on two typical structural forms. Next, geometric nonlinear analysis is conducted, demonstrating the symmetrical characteristic of failure modes, and the results are utilized to develop practical prediction formulas for the elastic buckling load. Finally, material and geometric nonlinear analysis is performed to examine the impact of parameters on structural stability performance. The sensibilities of the material nonlinearity, geometric dimension, geometric imperfection, and joint stiffness on the structural stability are illustrated. This study provides insights into the instability mechanism of such structures and offers valuable guidance for their design and application.

Case Study of Structural Design and Construction Process Analysis for an Aluminum Alloy Free Form Reticulated Shell of Nanjing Niushou Mountain

The aluminum alloy reticulated shell structure of Nanjing Niushou Mountain, the largest single-layer aluminum alloy reticulated shell in Asia, is 227m long from south to north, 130m spanning from east to west. In the design process, the aluminum alloy reticulated shells has been established, then the whole stability of the structure was analyzed to get the first six buckling modes and the safety factors through elastic and elastic-plastic analyses of the whole process. According to the complex construction conditions and the difficulties of construction for a super-large free form reticulated shell, a block fabrication accompanied by step-by-step launching erection process was introduced for economical and in-site safe construction. From construction economy, four different sliding systems have been prepared and compared to enhance the construction efficiency. Also four stages in each sliding system were assumed as their key construction steps through trial calculation and conceptual judgment. Thus, the construction process analysis model in each stage was analyzed and simulated respectively according to the key construction steps. The analysis results show that the safety factor of the reticulated shell structure meets the requirements of the specification, and that the selected sliding construction scheme satisfies the construction requirement on the special construction condition. This report provides an effective reference on future practical application.

Analysis and Calculation of Large Span Dry-Coal Shed

The project of Wuhan Group Kunming Iron and Steel Co., Ltd., Promote the supply side structural reform and implement the special upgrading project of environment comprehensive raw material yard project ore yard (A to B) reticulated shell structure Located in Kunming Steel New Area, Cao pu Town, Anning City, Kunming City, Yunnan Province, 780m long, 50m high, the span is 147m (more than 120m), According to «Code for Seismic Design of Buildings» and «Technical points of special review on seismic fortification of high-rise buildings beyond the limit», it belongs to the out of gauge large-span space structure, Special review of engineering seismic fortification is required. The structural analysis of the project adopts SAP2000, MST2020, MIDAS Gen three kinds of software for calculation and analysis, And the individual model and the whole model are established respectively, Envelope analysis is carried out for two cases. Through linear elastic analysis, response spectrum small earthquake analysis, Medium earthquake analysis of response spectrum, elastic time-history analysis of small earthquakes, dynamic elastoplastic analysis of large earthquakes to analyze and calculate the deformation of latticed shells and the stress of membersl. Through a series of structural analysis and structural measures, To ensure that the reticulated shell and the lower part are coagulated on the short column and all performance indicators can meet the specification requirements. Through the structural analysis of two calculation models, ensure that all performance indicators can meet the specification requirements.

Rotational performance of semi-rigid plate-type joints for reticulated shell structures composed of plate members

Manufactured by laser cutting technology with planar steel plates, the plate members have significant advantages in efficiency, customization, and transportation. These advantages make the plate members suitable for building small or medium-span curved reticulated shell structures. The plate members have been adopted in a novel reticulated shell structure with stiffening methods for resolving local buckling issues. In this type of structure, the semi-rigid plate-type joints are used to connect plate members. The previous study indicated that the rotational stiffness of plate-type joints has a great impact on structural stability. To investigate the rotational performance of the semi-rigid plate-type joints, a comprehensive study has been conducted in this research. Experimental tests were performed on a total of 12 specimens to obtain the moment-rotation responses of the joints. Four phases of the failure process were observed in the tests, namely, the linear elastic phase, slipping phase, hardening phase, and failure phase. The influences of joint width, joint thickness, and bolt diameter on the rotational performance are revealed by the experiments. Then, a refined finite element (FE) model was built and validated by the experimental results. This validated FE model clarified the failure mechanism of joints from the perspective of stress development and contact condition. Furthermore, theoretical formulas were established to calculate the key characteristics of the moment-rotation response, which is proved to have acceptable accuracy in predicting the rotational performance of joints. The conclusions of this study may provide a valuable reference for the structural stability design of reticulated shell structures composed of plate members.

Dynamic stability of single-layer spherical reticulated shell structures under earthquake action

In past decade, earthquake disasters have seriously damaged nonstructural components, so it is very important to study their dynamic stability. However, the existing researches mainly focus on the dynamic stability of multistory and high-rise buildings, and there are still deficiencies in the analysis of dynamic stability of reticulated shell structures under earthquake action. This paper takes the 40 m span K8 single-layer spherical reticulated shell structure with practical engineering significance as the research object, we study its dynamic instability characteristics under earthquake action, and propose a dynamic stability judgment method. The influence of various parameters on the critical loads of emotional stability of reticulated shell structures is systematically analyzed, including the impact of horizontal seismic action, the vertical seismic activity, and the three-dimensional seismic movement, considering the influence of material elastoplasticity; the result of different seismic inputs, the effects of initial geometric imperfections; the effects of varying rise span-ratio. In this paper, to investigate the nonlinear time-history response analysis, we uses the finite-element package ABAQUS. We first analyze the rise-span ratio as the dynamic stability of 1/3 single-layer reticulated shell structure under the action of the El Centro (1940) earthquake to reveal the dynamic loss of reticulated shell structure under earthquake action stable feature. The practical method for determining the proposed dynamic stability has a clear physical meaning and a range of applications. Our findings highlight that the critical load for dynamic stability under horizontal earthquake action is significantly lower than vertical earthquake action, and the critical load is the lowest under three-dimensional earthquake action. Material elastoplasticity influences the critical loads for dynamic stability of reticulated shell structures under different ground motions. The critical load of dynamic stability of single-layer structures with a larger rise-span ratio is lower, while those with a smaller one is higher. The initial geometric defects of the structure should be considered in practical engineering applications. The reticulated shell structure with a larger rise-span ratio needs to consider the dynamic stability problem in the strong earthquake area.

High-Speed Videogrammetry for Seismic Performance of the Spherical Reticulated Shell Structure on the Shaking Table

Spherical reticulated shell structure is an important structural form of large-span space buildings. It is of great significance to monitor three-dimensional (3D) dynamic responses of spherical reticulated shell structure to better understand its seismic performances, which will be helpful in the future to ensure the healthy condition of large-span space buildings during their lifespan. In this study, with the advantages of non-contact and high accuracy, a high-speed videogrammetric measurement method is proposed for monitoring the 3D dynamic responses of the seismically isolated, spherical, reticulated shell structural model. Two issues—the high-speed videogrammetric acquisition system and network configuration, as well as image sequence target tracking and positioning—are emphasized to achieve a cache of high-speed images and to improve the accuracy of tracking and positioning target points. The experimental results on the shaking table from the proposed method have been compared with those from traditional Optotrak Certus and accelerometers. The results prove that the proposed method is capable and useful for analyzing the seismic performance of spherical reticulated shell structures, as the dynamic responses monitoring accuracy of the method can reach the submillimeter level, with root mean square error values of 0.32 mm, 0.7 mm and 0.06 mm in the X, Y and Z directions, respectively.