scholarly journals A New Response Surface Stochastic Analysis Method for Spatial Structure Stability—The Reticulated Shell Structure as an Example

Buildings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 669
Author(s):  
Huijuan Liu ◽  
Nicola Tondini ◽  
Xisen Lu ◽  
Chunxiang Chen ◽  
Zhonggen Xu
Keyword(s):  
Response Surface ◽  
Shell Structure ◽  
Shell Structures ◽  
Spatial Structures ◽  
Analysis Method ◽  
Surface Method ◽  
The Stability ◽  
Reticulated Shell Structure ◽  
Modal Method ◽  
Random Defect

For a long time, spatial structures have been widely used. However, compared with the high strength of their material, their stability is weak, and especially sensitive to damage and defects. This feature has increased the engineering industry’s high requirements for their stability analysis. As we all know, this problem is more prominent for the reticulated shell structure, which is a classic representative of the spatial structure. However, in the current analysis methods for the stability of reticulated shells, the deterministic analysis method cannot consider the random characteristics of defects. Other random methods, such as the random defect modal method, and many improved methods, require more samples and calculation time. This unfavorable situation makes its engineering application greatly restricted. In addition, the random modal superposition method and derivation method based on Monte Carlo has not fundamentally changed this limitation. In order to fundamentally overcome this traditional shortcoming, this paper comprehensively studies the advantages of the high accuracy of the random defect modal method and the improved method, and at the same time, investigates the speed advantage of the response surface method, and then creates a new stochastic analysis method based on the response surface method. Finally, the analysis results of the calculation examples in this paper prove that it successfully balances and satisfies the dual requirements of accuracy and speed required for calculating the stability of the reticulated shell structure. Moreover, it has universal applicability to different forms of reticulated shells, such as classic 6-point flat domes, traditional reticulated shell structures, and bionic reticulated shell structures, and even other types of spatial structures.

Ultimate Load Analysis of Single-Layer Lattice Shells under Temperature Action

2012 ◽  
Vol 170-173 ◽  
pp. 2592-2596
Author(s):  
Shu Tang Liu ◽  
Qi Liang Long ◽  
Long Wang
Keyword(s):  
Temperature Change ◽  
Shell Structure ◽  
Single Layer ◽  
Cold Season ◽  
Change Impact ◽  
The Stability ◽  
Reticulated Shell Structure ◽  
Temperature Action ◽  
Important Measurement ◽  
Design Construction

Stability is an important measurement index of reticulated shell structure to security and reliability. Considering the temperature change, using structural buckling analysis in ANSYS, the stability of reticulated shell structure was invested. Analysis shows that stability of reticulated shell structure affected by temperature change impact; as the temperature goes down, the safety factor (stability coefficient) continually decrease. The conclusion showed that: 1) reticulated shell construction is suitable in summer; 2) Insulated curing of shell should be paid attention in cold season, and which will be useful on design, construction and use of structure.

Optimizing Nano Metalworking Emulsions Preparation Using Response Surface Method

2021 ◽  
Vol 39 (2A) ◽  
pp. 214-232
Author(s):  
Nuhad B. Dawood ◽  
Adnan A. AbdulRazak ◽  
Adel S. Hamadi
Keyword(s):  
Response Surface ◽  
Response Surface Method ◽  
Ph Value ◽  
Metalworking Fluids ◽  
Quadratic Model ◽  
Value Analysis ◽  
Surface Method ◽  
Hydrophilic Lipophilic Balance ◽  
The Stability ◽  
Nano Emulsion

Nano emulsions (NEs) have important prospective advantages for assured industrials applications especially Metalworking fluids (MWFs), due to their Nano size, stability, than other types of traditional emulsions. In this work paraffin oil, water and mixture of surfactants Span20 & Tween20 are utilized for preparation of the MWF. A quadratic model was developed by applying the response surface method (RSM) to relate the droplets size and emulsion stability as a response to five independent variables namely the speed and time of mixing, concentration of the surfactant, Hydrophilic-Lipophilic Balance (HLB) value and pH value. Analysis of variance (ANOVA) was conducted; the results confirm the high significance of the regression model. The predicted values were found to be satisfactory with that experimental value. Mixing speed exerted the highest effect on the droplet size and the stability of the emulsion. The optimum conditions were found be (the concentration = 4.75 wt.%, time of mixing = 18.12 min, speed of mixing 14998.93 rpm, pH = 10.01 and HLB = 10.87) to attained Nano emulsion with 2 nm in size and stability of 24 days. Tool wear and surface roughness were studied at different speed, the results have showed that the wear ratio of the bits for all selected speeds is as follow: using commercial fluid > MWFs. The metallurgical microscope images have showed that, in case using MWFs the surface of cracks between the metals and the tool is more smooth compare with other fluids

Safety Analysis on the Variable Constraint Space Reticulated Shell Structures

2011 ◽  
Vol 368-373 ◽  
pp. 1613-1616
Author(s):  
Xiu Li Wang ◽  
En Ping Jin ◽  
Yan Peng Zhu
Keyword(s):  
Shell Structure ◽  
Reference Value ◽  
Shell Structures ◽  
Optimized Design ◽  
Quality And Safety ◽  
Analysis Method ◽  
Long Span ◽  
Temporary Support ◽  
Multiple Variable ◽  
Constraint Structure

During construction, the spatial shell structure is the variable constraint structure system. In order to guarantee the construction quality and safety, its addition or disassembly scheme of temporary support must be optimized design. Based on variable constraint structure analysis method, the paper simulated and analyzed possible multiple variable constraint scheme during the long-span space reticulated shell structural construction, and put forward the principle and method abide by addition and disassembly design of temporary support. For other variable constraint structures similar to the spatial shells, the principle and method proposed has a very great reference value.

An Improved Reliability Analysis Method for Mooring Dolphin Structures

2014 ◽  
Vol 136 (3) ◽  
Author(s):  
Reda Farag ◽  
Achintya Haldar ◽  
Mahmoud El-Meligy
Keyword(s):  
Reliability Analysis ◽  
Response Surface ◽  
Response Surface Method ◽  
Hybrid Approach ◽  
Evaluation Procedure ◽  
Analysis Method ◽  
Analysis And Design ◽  
Surface Method ◽  
Reliability Method ◽  
Improved Response Surface Method

A novel reliability evaluation procedure is proposed for analysis and design of offshore mooring dolphin structures (MDS). It is a hybrid approach consisting of an improved response surface method (IRSM), second-order reliability method (SORM), and several advanced factorial schemes. It is denoted as IRSM-SORM. Several schemes of IRSM-SORM are proposed and clarified with the help of an illustrative example.

Research on Vibration Parameters of Tamping Operation

2015 ◽  
Vol 724 ◽  
pp. 283-286
Author(s):  
Tao Yong Zhou ◽  
Bin Hu ◽  
Yong Xin Peng ◽  
Bo Yan
Keyword(s):  
Response Surface ◽  
Response Surface Method ◽  
Optimization Method ◽  
Analysis Method ◽  
Important Work ◽  
Railway Ballast ◽  
Surface Method ◽  
Vibration Parameters ◽  
Railway Maintenance ◽  
Effective Analysis

Tamping operation is an important work of railway maintenance. There are many factors that can influence the tamping effect. This paper mainly studies the influence of vibration frequency and amplitude on the porosity of railway ballast. In order to obtain the minimal porosity, the response surface method was used to seek the optimal vibration parameters. Using an optimization method, the optimum vibration parameters were obtained that gives the minimal porosity. The obtained results are consistent with those of other similar studies, which mean that the response surface method is an effective analysis method of multi-parameter optimization problem under tamping operation.

Experimental Analysis on Mode Localization of Damaged Reticulated Shell Structures

2011 ◽  
Vol 243-249 ◽  
pp. 1301-1304
Author(s):  
Zhuo Wang ◽  
Wei Ming Yan ◽  
Lie Ping Ye
Keyword(s):  
Shell Structure ◽  
Single Layer ◽  
Shell Structures ◽  
Scale Model ◽  
Physical Parameters ◽  
Structural Stiffness ◽  
Assessment Index ◽  
Mode Localization ◽  
Reticulated Shell Structure ◽  
Structural Mode

The damage of reticulated shell structure will arouse structural mode localization. The quantitative assessment index of mode localization is defined. A scale model experiment for mode localization is carried out on a Kiewit single-layer spherical reticulated shell structure, and the features of mode localization are studied. Four cases about structural stiffness’ change are constructed in the experiment, and three structural modals are obtained at random. The localization of the three modes is analyzed under each case. The results show that slight changes of physical parameters are likely to arouse obvious localization of some modes for reticulated shell structure.

scholarly journals Influence of welding deformation on anti-collapse performance of single-layer reticulated shell structures with prestressed cables

2021 ◽  
Vol 2045 (1) ◽  
pp. 012018
Author(s):  
Y Q Fu ◽  
X D Yang ◽  
H D Zhang ◽  
Y M Wang
Keyword(s):  
Finite Element ◽  
Shell Structure ◽  
Single Layer ◽  
Shell Structures ◽  
Welding Deformation ◽  
Finite Element Software ◽  
Reticulated Shell Structure ◽  
Prestressed Cable

Abstract In this paper, the ABAQUS finite element software is used to model and analyze the single-layer reticulated shell structure. And the method of removing the constraints of key components is used to analyze the anti-continuous collapse performance of this reticulated shell structure under the action of geometric defects and welding deformation. Welding deformation is mainly caused by welding and prestressed cable tensioning of single-layer reticulated shell. The results show that the removal of the key columns under the reticulated shell will lead to the continuous collapse of the upper part, which leads to the continuous collapse of the whole structure, and the welding deformation can make the continuous collapse of the whole reticulated shell more obvious. Thus determining the influence of geometric defects and temperature shrinkage deformation on the anti-continuous collapse performance.

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

2019 ◽  
Vol 23 (6) ◽  
pp. 1098-1113
Author(s):  
Xin Chen ◽  
Xuanneng Gao ◽  
Xiang Lin ◽  
Jingliang Liu ◽  
Lihui Le
Keyword(s):  
Shell Structure ◽  
Dynamic Responses ◽  
Vibration Period ◽  
Dynamic Displacement ◽  
Symmetrical Structure ◽  
Displacement Response ◽  
Influence Line ◽  
Surface Method ◽  
Novel Method ◽  
Reticulated Shell Structure

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.

scholarly journals Formulation and Characterization of Oil-in-Water Emulsions Stabilized by Saponins Extracted from Hedera Helix Algeriensis Using Response Surface Method

2020 ◽  
Vol 10 (5) ◽  
pp. 6282-6292
Keyword(s):  
Response Surface ◽  
Response Surface Method ◽  
Viscoelastic Behavior ◽  
Surface Characteristics ◽  
Rheological Parameters ◽  
Triterpene Saponins ◽  
Hedera Helix ◽  
Surface Method ◽  
Oil In Water ◽  
The Stability

Triterpene saponins extracted from Hedera helix Algeriensis plants were evaluated in terms of surface characteristics and capacity to be utilized as surfactants for the formulation of oil-in water emulsions. Surface tension and emulsifying properties were used for the identification of the surfactant characters, while emulsions were characterized by rheological methods and their stability was estimated by the control of the creaming index. The design of emulsions was conducted by employing a response surface method (RSM). The factors affecting the rheological parameters and emulsion stability were carefully evaluated by the polynomial models. Triterpene saponins were found as effective biosurfactants; they contribute strongly to the stability of emulsions by interacting with other excipients. Emulsions exhibited a shear-thinning behavior and low apparent viscosities which depend on the amount of xanthan used. They were considered as weak gels with a viscoelastic behavior. In addition, it was found that the presence of a sufficient quantity of saponins improves the stability of emulsions.

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