Reticulated Shell Structure Research Articles

Failure Analysis of the Top Reticulated Shell Structure of a 20,000 Cubic Meter Floating Roof Storage Tank

The single-layer spherical reticulated shell structure is used as the fixed roof of a 20000 m3 internal floating roof tank. In the process of inspection and maintenance, the reticulated shell collapsed. In this paper, the strength, stiffness and stability of the design structure of the tank roof reticulated shell are calculated based on the finite element model, and the weak points of the shell structure are revealed, and the failure causes of the shell structure are comprehensively analyzed.

Probabilistic seismic analysis of single-layer reticulated shell structures controlled by viscoelastic dampers with an effective placement

In this paper, an effective placement of viscoelastic dampers on single-layer reticulated shell structures is proposed to mitigate seismic response. For comparison, an existing placement of viscoelastic dampers is also investigated. The effectiveness of the proposed placement of viscoelastic dampers is investigated from both deterministic and probabilistic perspectives. The single-layer reticulated shell structure is driven by the stochastic seismic ground motions, which are modeled via the random function based spectral representation method. The probability density evolution method is then implemented for probabilistic response and reliability analyses of the shell structure. A series of deterministic numerical simulations are first implemented under different earthquake excitations, including both actual and artificial seismic ground motions, to compare the control effects in deterministic sense. Then, the control effects of the proposed placement and the existing placement are compared in probabilistic sense, where the probabilistic responses, equivalent extreme value distributions and failure probabilities are extracted. Numerical results demonstrate that the seismic performance of the shell structure can be greatly improved by arranging the viscoelastic dampers with the proposed placement.

Performance-Based Analysis of Single-Layer Cylindrical Steel Reticulated Shells in Fire

With the rapid development of architectural technology, long-span structures have been widely used due to their vast interior space and beautiful architectural composition. Due to the characteristics and high costs of coating materials on large steel structures, fire resistance designs for these kinds of structures have become more and more important. This paper presents comprehensive case analyses of the fire performance of single-layer cylindrical reticulated shells. Nonuniform fire temperature fields of single-layer cylindrical reticulated shells in different fire scenarios were generated using a Fire Dynamics Simulator (FDS). The influences of different parameters on the air temperature field during a fire in a reticulated shell structure were analyzed. A Finite Element (FE) model was developed using the FE software ABAQUS to model the structural behavior of single-layer cylindrical reticulated shells in different fire scenarios. The effects of various parameters on the responses of single-layer cylindrical reticulated shells during a fire were investigated. Using the results from the performance-based analysis in this research, we propose some recommendations for fire resistance designs for single-layer cylindrical reticulated shells.

Hysteretic behavior of bolt–column joints under in-plane loading combinations by experimental and numerical study

The bolt–column (BC) joint has enough bending stiffness satisfying large-span single-layer reticulated shell structure well. The hysteretic behavior of BC joints under different in-plane combinations of bending moment and axial force is investigated in this study. Firstly, precise finite element models (FEM) of the BC joints, which considered the material and the geometric and contact nonlinearities, were established in ABAQUS. The failure modes, hysteretic curves, skeleton curves, and bearing capacity for assessing the joint hysteretic behavior were investigated in detail by the numerical analysis. BC joints under different combined axial force and cyclic bending loads were studied by numerical analysis to obtain the impact of the axial force, which provides necessary technical support for engineering practice. Three tests were conducted and the results verified that the FEM was effective in simulating the joint behavior by comparison with the test results. The research shows that the hysteretic capacity of BC joints under in-plane bending is weaker than that under out-of-plane bending, but the bearing capacity of former is higher. Increasing the thickness of the side and middle plates can slightly enhance the joint in-plane hysteretic capacity, which is improved with small axial compression and reduced with high axial compression and axial tension.

Parametric static analysis of a new type of fabricated plate grillard thin shell roof structure

The new fabricated slab ribbed shell roof structure is a new structure based on a large-span steel-concrete composite thin shell roof. An assembly unit composed of a thin-walled steel ribbed plate, a base plate, and concrete provided with bolt holes, and a plate-grid thin shell roof structure formed by the assembling and connecting assembly units. Considering the influence of the structure’s rise span ratio, five groups of rise span ratios were used for finite element analysis and compared with single-layer cylindrical reticulated shells. The analysis shows that the mean value of the ultimate load of the new prefabricated panel latticed thin shell roof structure is increased by 5.3% on average compared with the single-layer cylindrical reticulated shell structure. When the rise span ratio is 1/5, the structure has the largest stiffness and the smallest deformation; when the rise span ratio exceeds 1/5, the growth trend in the ultimate load that the structure can withstand will become smoother, and the average maximum displacement will decrease by 4.3% compared with the single-layer cylindrical reticulated shell, which shows that the grid lattice structure has better stiffness.

Parametric Design and Static Performance Comparison of Six Typical Spherical Semi-open Reticulated Shell

By using ANSYS Parametric Design Language (APDL), this paper compiled the parametric design macro program for six types of single-layer semi-open spherical reticulated shell structure. Parametric design of the six types of reticulated shell structure was realized with given parameters of span S, the vector high F, radial node cycles number Nx, ring to symmetric regional copies number Kn, and the upper removed laps Ns. The stress performance of the six types of reticulated shell structure was compared and analyzed. Modelling examples demonstrated that the parametric design macro program is simple, practical and improves the efficiency of the selection of the reticulated shell design and the stress analysis under different geometric parameters. Through the comparative analysis of stress performance, some conclusions with engineering significance were obtained.

A novel method for rapidly calculating explosion dynamic displacement response of reticulated shell structure based on influence surfaces

In order to analyse the mechanical behaviour of a reticulated shell structure under explosive load, a novel method was proposed to calculate the dynamic displacement response of the cylindrical reticulated shell structure by using the influence surface in this article. First, the theory of the dynamic influence line was developed and the consistency between the dynamic influence lines and the static ones was verified. Then, based on the theory of the dynamic influence line and for the simplified calculation of dynamic responses, the dynamic influence lines of a simply supported beam were simplified as the static ones multiplied by the dynamic amplification factor β. And then the explosion dynamic responses of the beam could be fast calculated using the influence lines. The extended application of the above method to single-layer cylindrical reticulated shell was the influence surface method. The results of numerical examples showed that the nodal displacements of the structure obtained by using the influence surface method agreed well with those obtained by using ANSYS/LS-DYNA. The research results also indicated that the influence surface method was applicable to the node displacement calculation of the structure under three different conditions, including the centre node of the symmetrical structure, the arbitrary nodes (excluding those near the supports) of symmetrical structure under symmetrical loads and the arbitrary nodes of arbitrary structures in which the load holding time is much longer than the natural vibration period of structure. The proposed approach could reduce the computation cost for analysing the explosion dynamic response of the reticulated shell structure, thereby providing a more effective method for the anti-explosion design of reticulated shell structures.

Connection Performance of Bolted Aluminum Alloy Honeycomb Panel-Beam Composite Structure

A convenient and reliable connection between panels and beams was investigated for collaborative work of single-layer composite reticulated shell structure in which aluminum alloy honeycomb panels participate. In the paper, the "self-tapping bolt" connection was adopted to realize the "tight fit" performance of connection effectively in the composite structure. Through three groups of bearing capacity test on 1.5 m×3 m square meters of the aluminum alloy honeycomb panel-square tube beam combined structure, the force characteristics and failure mechanism of the structures were studied. The experimental results revealed that the connection method could ensure effective transmission between the panel and the beam which made them work in excellent condition. In order to simulate complex performance connection with the panel-beam composite structure, tangential and normal contact behavior were considered at the bolt connection point between the honeycomb panel and the beam in ABAQUS analysis. The analysis results illustrated that the finite element results had the highest matching degree with the experimental values when the friction coefficient of the joint boundary was 0.25. The finite element analysis of the connection bolts spacing indicated that the economic and excellent connection effect can be achieved when the spacing was about 90 mm.

Dynamic Response Analysis and Model Test Research on K6 Single-Layer Spherical Reticulated Shells Subjected to Impact Load

To study the dynamic response characteristics and failure process of single-layer spherical reticulated shells under impact loads at different loading points, impact dynamic analysis and experimental study are conducted on the K6 single-layer reticulated shell structure. First, the basic theory of numerical calculation and the model parameters are described. Then, dynamic response analysis under impact load is done by choosing different impact points. Finally, the impact test is performed on a large-scale shell model, dynamic response data of key members and nodes of shell structure are obtained, and the shell deformation and destruction process is recorded by a high-speed camera. The results show that the structural dynamic response gradually increases farther from the base point under the same impact force. The nearer the impact point is, the earlier the response occurs, and the larger the corresponding amplitude will be. The apex is the most unfavorable impact loading point, and the member at the apex should be strengthened for impact resistant design of the reticulated shell. The transmission time of the impact dynamic response from the impact site to the entire reticulated shell is short.

温度应力对螺栓球网壳结构的影响分析

温度应力对螺栓球网壳结构的影响分析

Study on Seismic Response of Single-layer Cylindrical Reticulated Shell Due to Horizontal One-dimensional Earthquake

A single-layer cylindrical reticulated shell structure model was established by selecting real seismic waves and using ANSYS structural analysis module, and the structural model was subjected to multi-point earthquake input and consistent input time history response calculations. The result shows that in the seismic design of large-span space structures, the traveling wave effect must be considered. When the traveling wave effect is studied, if we only pay attention to the maximum axial force of the structural member, horizontal one-dimensional input can be performed.

Study on Explosion Effects of a Spherical Reticulated Shell Under Internal Explosions

Due to the propagation characteristics of explosion shock waves, the stiffness of the structure and its components has an important influence on the explosion effects of the reticulated shell. However, the current research on this problem is insufficient. In this paper, a parametric model for the numerical simulation of spherical reticulated shell structure under internal explosion was established using the finite-element software. Based on the built model, the dynamic responses of a spherical reticulated shell under internal explosion were numerically simulated and analyzed. In addition, the influence of the stiffness of the reticulated shell bars, the stiffness of the connectors, and the stiffness of the roof panels on the explosion effects of the spherical reticulated shell structure under internal explosions were researched. The results show that with an increase in the flexural stiffness of the reticulated shell bars, the kinetic energy and the maximum node displacement responses of the spherical reticulated shell are reduced. However, the magnitude of these decreases gradually decline. The results also reveal that the greater the stiffness of the connectors, the greater the internal energy, the kinetic energy and the maximum node displacement responses. The increase in the stiffness of the connectors is disadvantageous to the anti-explosion properties of the spherical reticulated shell structure. In addition, the research indicated that there is a threshold value to the stiffness (thickness) of the roof panels with regard to the influence of the explosion effects of the spherical reticulated shell, in the case of a certain amount of explosives. With an increase in the stiffness (thickness) of the roof panels, the displacement responses of the spherical reticulated shell under internal explosion decrease if the stiffness (thickness) of the roof panels exceeds the threshold value. Finally, some suggestions for explosion proof and anti-explosion design of the long-span spherical reticulated structures are proposed.

Dynamic response of single-layer reticulated shell with explosion-protection wall under blast loading

To investigate the structural dynamic response of long span reticulated shell under external blast loading considering explosion-protection wall, explicit finite element (FE) programme LS-DYNA is used to set up the analytical model of explosion-protection wall corresponding to an experiment to grasp the propagation law of blast shock waves around the wall. The results of simulation and experiment are compared and the results verify the creditability and applicability of numerical simulation by using ALE (Arbitrary-Lagrange-Euler) algorithm. A Kiewitt8 single-layer reticulated shell of refinement with span of 40 m is established to simulate the responses of structure considering explosion-protection wall, which contains reticulated shell member, purlin hanger, purlin, rivet and roof boarding. According to simulation results from the maximum nodal displacement, average plastic strain and yielding degree of cross section of reticulated shell member, the dynamic response laws are proposed based on varying parameters, including height, position, length, material of the explosion-protection wall, rise-span ratio of reticulated shell and TNT explosive weights. Meanwhile, the influence rules of explosion-protection wall and structure on diffraction and reflection action of blast shock wave are obtained. In addition, the adverse height of the explosion-protection wall for reticulated shell with span of 40 m under external blast loading is proposed. Four damage types of reticulated shell with the explosion-protection wall subject to external blast loading are defined by summarizing all the structural response of FE numerical models, which could provide reference for reasonable explosion-proof design for reticulated shell structure.

Progressive Collapse Analysis of Reticulated Shell Structure under Severe Earthquake Loading Considering the Damage Accumulation Effect

A reticulated shell is one of the conventional long span space structures, prone to progressive collapse under a severe earthquake due to its unique single layer feature. This is. However, the collapse mechanism of this type of structure is not well studied. In this paper, a numerical modelling technique using the fiber beam elements is developed. The correspondent material model based on the inclusion of damage accumulation was also developed in order to determine the failure criteria of structural members. An effective way to simulate the buckling behavior of the structural members is also used in the numerical simulation. The relevant numerical method is developed and validated against experimental tests: good agreement is achieved. Based on this numerical method, a parametric study of the reticulated shell under severe earthquake loading is performed and the responses of the structure is investigatedand a three-stages collapse mechanism of this type of structure was observed.

基于环境激励单层柱面网壳结构的模态分析

网壳结构因其杆件众多，其动力学参数频率和振型比较密集，采用力锤激振方法因其能量过小不易获取其模态参数。环境激励法不需要特别的激振设备，仅仅依赖于地脉动，信号覆盖的频带较宽,因而能够有效地识别出了复杂结构模态参数。本文基于环境激励法进行单层柱面网壳结构模型的模态分析并与有限元模态分析结构比较，验证了基于环境激励模态分析的有效性。 Because of the large number of bars, the frequencies and the mode shapes of the shell structure are very dense, and it is difficult to obtain the modal parameters due to the small energy based on hammer excitation. The ambient excitation method does not need special excitation equipment, only depends on the micro tremors, and the frequency band of signal coverage is wide. In this paper, based on the ambient excitation method, the modal analysis of single-layer cylindrical reticulated shell structure is carried out and compared with the finite element modal analysis. The effectiveness of the modal analysis based on ambient excitation is verified.

Modeling geometric imperfections for reticulated shell structures using random field theory

The load-carrying capacity of shell structures and shell-like space frames can be sensitive to initial geometric imperfections. Conventional methods of modeling geometric imperfections have focused on estimating the lower bound of the load-carrying capacity of reticulated shells. This paper proposes a random field model for the initial geometric imperfection of reticulated shell structures. The model accounts for the spatial distribution of the initial geometric imperfections, in which the correlation between imperfections at two different nodes depends on the length and number of the connecting members between the two nodes. The paper also presents the findings of the measurements of the initial geometric imperfections of a real reticulated shell structure. Based on the measurement data, the statistical characteristics of the random field model are determined. The role of initial geometric imperfections on structural ultimate strength is examined using numerical examples.

Analysis on complex structure stability under different bar angle with BIM technology

Summary Sun Valley, the landmark building of World Expo in Shanghai, which has free surface with single-layer reticulated shell structure, is a typical complex structure. CAD/CAM integrated information system to design is used for the complex structure; however, it is a very rigorous process to be used widely. The relevant technology of the Sun Valley is not open to the public at present, so we try to use BIM technology to model the Sun Valley, including architecture modelling and structure analysis. By analysis of the Sun Valley structure using this method, it is proved that the problems in modelling may be solved by writing some script codes in Rhino software and the stability of the model can also be analyzed. The new approach is viable and effective in combination with different softwares such as Rhino, Revit, and Midas in solution of the complex shaped surfaces’ structure for modelling and calculation.

Thermal and integral lifting analysis of a lattice shell lighting roof based on genetic algorithm and probabilistic design

The optimum analysis for Railway Station Building of Yujiapu (a shell-shaped single-layer reticulated shell structure) was conducted based on genetic algorithm. An elitist genetic algorithm was used by combining Matlab and a general finite element software ANSYS. Analysis was firstly conducted to study the influence of temperature load on support reaction force, then the optimal combination of support stiffness to minimize the effects of temperature load was derived by using GA. Subsequently, probabilistic design analysis was conducted for the integral lifting process and the key lifting points which influence the stress of lifting zone significantly was derived, at the same time the probability distribution model of lifting height difference was established and validated. Finally, the same genetic algorithm was adopted to optimize the combination of lifting height difference, the maximum stress of lifting zone will be reduced obviously by using the computed results. The efficiency and applicability of GA in optimization of complex structures were demonstrated in this paper.

Experimental study on lead extrusion damper and its earthquake mitigation effects for large-span reticulated shell

A Lead Extrusion Damper (LED) is experimentally studied under various frequencies and displacement amplitudes. Experimental results show that the force-displacement hysteresis loops of the LED are close to rectangular and the force-velocity hysteresis loops exhibit nonlinear hysteretic characteristic. Also, the LED can provide consistent energy dissipation without any stiffness degradation. Based on the experimental results, a mathematical model is then proposed to describe the effects of frequency and displacement on property of LED. It can be proved from the comparison between experimental and numerical results that the mathematical model can accurately describe the mechanical behavior of LED. Subsequently, the seismic responses of the Schwedler reticulated shell structure with LEDs are analyzed by ANSYS software, in which three different installation forms of LEDs are considered. It can be concluded that the LED can effectively reduce the displacement and acceleration responses of this type of structures.

Analysis on the Parametric Design and Static Performance of the Hyperbolic Paraboloid Shells with Rectangular Projection

This paper first used parametric design language APDL to establish three kind of the single hyperbolic paraboloid shell model with rectangular projection. The parametric design of the reticulated shell structure could be realized after inputting the span (S),rise (F),the grid number of each side (Kn),the warping rate (K),which provided great convenience for optimizing the structure and force analysis.Then through contrasting three structure schemes and different warping rate,it studied how they influence the mechanical properties of structure.And at last it got some conclusions with engineering significance.