Research on Behavior of Elasto - Plastic Stability of Schwedler Domes

More than 400 tests for the complete-process analysis considering geometry nonlinearity and material nonlinearity of Schwedler single-layer latticed domes with various geometries have been carried out and the critical load is obtained.The effect of initial imperfection,asymmetric load distribution,especially the effect of material nonlinearity on the stability behavior of this kind of domes is considered,and the rule about the elasto-plastic stability behavior is concluded.Based on the work introduced in present paper,people can get useful information for engineering design or theoretical study.And some conclusions could be drawn:(1)To ensure security of the dome,the critical load of the dome must be confirmed by the complete-process analysis considering geometry nonlinearity and material nonlinearity;(2) Schwedler single-layer latticed domes belongs to structure of imperfection sensitivity;(3) The critical load of the dome is affected a little by the asymmetric load distribution;(4)The effect of change of supporting condition on the critical load of the dome should be considered properly in engineering design.     

Design of Double Layer Torsional Reticulated Shell Using Back- Propagation Neural Network

In this paper artificial neural networks are used for design of large span double layer torsional reticulated shell. The torsional reticulated shells with spans varying between 50.0 - 80.0m are considered, Back -propagation algorithm is employed for training efficient neural networks for evaluation of the maximum deflection, weight and design of double layer torsional reticulated shell. A special method is developed for data ordering to reduce the nonlinearity of data and to increase the speed of training. This approach also provides the necessary stability. It shows that it is feasible to design double layer reticulated shell with artificial neural networks.     

Preliminary Optimization of Partial Single layer Reticulated Shells Based on Uniform Design[JP]

Size, shape and topology optimizations are involved in the structural design of partial single layer reticulated shells. To meet the requirements of computation efficiency during preliminary design, a uniform design method was adopted to achieve multi level optimization. Only existing software packages for reticulated shells were used in the experiment design. By regressing the computing data, approximate functional relations between the indexes (steel weight, deflections, basic frequency, and minimal nonlinear buckling load) and variables (rise of the shell, single layer area, and design stress ratio for single layer members) were obtained. The best combination of the variables was acquired by solving a simple programming problem. Comparative design of a multipoint supported hexagonal reticulated shell verified the efficiency and reliability of this approach.     

Truss Structure Shape Optimization withDifferential Evolution Algorithm

Differential Evolution (DE) was introduced to get the global optimum and overcome the difficulties encountered by coupling two types of design variables in the shape optimization of truss structures with stress, geometry, and local stability constraints. The basic principle of DE algorithm was presented in detail first, and then mathematical model for shape optimization of truss structures was presented, in which two types of design variables, such as the node coordinates and section areas, were considered simultaneously. Several classical problems were solved with DE algorithm, and the results were compared with those using the other optimization methods. It was shown that DE algorithm had good convergence and stability and could be applied for shape optimization of truss structures effectively.     

空间高度对球面网壳结构内爆炸响应的影响

基于修正后的Johnson-Cook材料模型，应用ANSYS/LS-DYNA建立K8型单层球面网壳计算模型，对内爆炸下不同空间高度的结构爆炸响应进行计算和分析。首先，分析结构内爆炸冲击波传播规律，验证模型参数选取的可行性；其次，讨论内爆炸作用下球面网壳的动力响应，对比分析不同本构模型对爆炸响应的影响；最后，定义下部支承结构所围体积占结构所围总体积的比值为空间高度系数，讨论空间高度系数对墙面未开洞和墙面开洞球面网壳动力响应的影响。结果表明，爆炸冲击波在球面网壳结构角部有汇聚效应，与反射冲击波共同作用，严重影响球面网壳结构的动力响应；对于墙面未开洞的球面网壳，爆炸响应受反射冲击波影响较大；对于墙面开洞的球面网壳，爆炸响应受空间高度系数影响较大。基于研究结果给出了球面网壳结构在内爆炸下防爆和抗爆设计的合理空间高度系数建议值。     

Review on the Preparation and Application of Carbon Membrane

Based on structure analysis software ANSYS, a non-linear complete-process analysis of stability behavior of single-layer latticed domes with different span and different rise-span ratio and different section is carried out. The effect of unsymmetrical loading distribution to the stability behavior of single layer latticed domes with various parameters is also analyzed. Some important conclusions are acquired and can be used as guidance to engineering design.     

THE FUZZY OPTIMIZATION DESIGN OF BOX EXPANSION ARM OF CRANE TRUCK

In this paper the section sizes of box expansion arm of crane truck are optimized in order that the weight of the arm will be the lightest on conditions that strength, rigidity, stability and size constraints are satisfactory. The fuzzy factors which influence design and the fuzziness of constraint conditions are considered. The unsymmetry mode of fuzzy optimization is established and solved by the method of optimal level cut set. Examples show that the effect is notable.     

Determination of the Binding Constant Between Sodium Houttuyfonate and Human Serum Albumin by Capillary Electrophoresis

The objective function of minimum cost is established for double layer torsional reticulated shell, taking the rise-span ratio, grid size and shell thickness as design variables. Based on the exhaustion and 0.618 methods, the computing program LSD has been developed. For the double layer torsional reticulated shell with the span of 50 m to 80m, the optimal grid size and thickness have been obtained for systems of light roof materials with different spans. Empirical formulas are deduced from the results.     

Parameter Optimization Analysis of Viscous Dampers for Dissipation Structure

The design method of parameter optimization of nonlinear viscous dampers for dissipation structure was analyzed based on response surface methods. The method included experimental design, finite element analysis, fitting the response surface function and parameter optimization. Taking a reinforced concrete frame structure for an instance, the mathematical model of parameter optimization of viscous dampers for dissipation structure was established by taking the minimum all damping force as objective function and taking the interlayer maximum displacement less than limits as constraints, and then the damper parameters were optimized using the method of nonlinear programming optimization. The results show that the method of parameter optimization of viscous dampers based on response surface method can ensure the structural displacement is less than limit and the construction cost can be reduced.     

Effects of Spherical Joint Stiffness on Seismic Response of Single-Layer Cylindrical Reticulated Shell Changing with Peak Ground Acceleration

The previous studies find that the hollow spherical joint stiffness has a certain influence on seismic response of single-layer cylindrical reticulated shell. In order to analyze the rule of this influence with PGA (peak ground acceleration) changing, two types of finite element models are built. The two types of models have the same size except the spherical joint. The first type is a fine model built by shell element and its spherical joints and tubes are built by considering the real size; the other type is the common model which is built by beam element, and the spherical joints are neglected. Comparing with the seismic response of the two types of models when PGA changes, the results show the difference between the two types of model in node displacement-time curves is increased as PGA increases; when the PGA is larger than the collapse acceleration of structure, the influence of increasing joint wall thickness on improving the structural capacity of anti-stability is decreased as PGA increases.     

Application of a Particle Swarm Optimization Algorithm in Truss Structure Optimal Design

The particle swarm optimization (PSO) algorithm developed in recent years is a stochastic optimization algorithm based on swarm intelligence. It possesses advantages such as being a simple concept, ease of implementation and low resource occupation. The PSO algorithm was adopted to solve the problem of size optimization of truss structures with stress and displacement constraints. We present the basic principle of the original PSO algorithm in detail, and then introduce a constriction coefficient to modify it. Moreover, reasonable values of the coefficients are proposed for the modified PSO algorithm. Several classical problems are solved using the modified PSO algorithm, and the results compared with those using traditional optimization algorithms and genetic algorithms. Numerical results show that the modified PSO algorithm has good convergence and stability, and can be applied to the size optimization of truss structures.     

Surface Reconstruction and Application Based on Shape Constraints

On the base of the fairing of free-form surface reconstruction from 3D data points, this paper probes one method based on shape constraints. By making physical model as objective function and using geometric constraints, free form surface reconstruction is realized based on the idea of energy optimization. This method is not only beneficial to the connection of the reconstruction surface and CAD/CAM system, but also to the integration of design, manufacturing and inspection.     

Fire-resistance performance of high-strength-steel H shaped columns under the axial compression

In order to investigate the fire-resistance performance of high-strength-steel column,this paper deduces the critical stress of high-strength-steel columns under the axial compression at high temperature by introducing the mechanical properties of high-strength-steel at high temperature.Moreover,coefficients of overall stability and critical temperature for high-strength-steel column under the axial compression are obtained which can provide a reference for design.The comparison of overall stability coefficient and critical temperature between high-strength-steel and normal steel is made.The results show that the overall stability coefficient and critical temperature for normal steel is not applicable for high-strength-steel,and the overall stability coefficient for high-strength-steel is smaller than that for normal steel.The paper uses the finite element analysis to validate the overall stability coefficient,and good match was found between them.     

Estimation of Earth Work Volume and Design Elevation in Large Earth Work

In this paper,the approximation calculation method based on calculation model of earthwork formula of tetragonal prism is described. The optimization design elevation in large earthwork can be determined by this method. Through introducing a set of different design elevations, the difference between and sum of the total excavation and the total fill can be calculated. An economical analysis is carried out on the design elevation chosen with little value for both cases by numerical values comparison. The elevation with the lowest cost is taken as the optimal design elevation.     

Optimization of quenching parameters for ultra high strength steel using response surface method

In order to optimize the quenching parameters of ultra high strength steel 22MnB5,orthogonal experimental design method is applied to design the experiments and response surface methodology (RSM) is used to analyze the experimental results. Austenitizing temperature and soaking time are taken as the optimization factors. The effect of these factors on quenching hardness and elongation are investigated. The optimization results of each single objective are firstly obtained. Then,ideal point method is used to find the solution to the multi-objective programming,and global optimums are gained. Finally,the optimal results are discussed from the microstructure angle and the reliability of the prediction models is demonstrated.     

Efficiency of product collaborative innovation design based on the attribute and matching task

The degrees that the design agent capacity matches the design task are an important factor affecting the efficiency of collaborative product innovation design. The classification and quantitative calculation of different types of design agent capacity combination is carried out after the characteristic of design agent is analyzed. An efficiency model whose goal is the shortest entire time is constructed based on the definition of task attribute,and then the solving method of efficiency model are designed based on particle swarm optimization algorithm. The collaborative product innovation design of cabin is taken as an example to prove that considering the matching agent attribute with task can shorten the design cycle and improve design efficiency.     

Fuzzy Optimization for Reliability Apportionment of Series system

This paper points out that there are many factors which affect the reliability optimization apportionment of the series system which is in nature a problem of fuzzy optimization. In the light of this paper puts foreword a method for the reliability apportionment of the series system. Moreover, it is discussed with fuzzy optimization apportionment of the system reliability under the conditions of given source constraints.     

The Practice of Planning and Design of Characteristic Rural Areas in Jiangsu Province: A Case Study of Shiye Town,Zhenjiang City

Based on the theory of three living spaces,taking the characteristic rural areas of Shiye Town in Zhenjiang City as the research object,the study analyzed its constituent elements in production,life and ecological space (three living spaces) and put forward the strategy of space optimization.The overall optimization design of the village is made according to the problems by combining with the current situation of pilot villages such as Yongmaowei,Huanqingzhou and group 1 of Xianfeng Village.In addition,special reconstruction measures were formulated for the existing problems of agricultural houses and public spaces in various typical villages.     

Renovation of Road Landscaping in Old Downtown Areas of Mountainous Cities:A Case Study of Pengshui County,Chongqing Municipality

Current situation of road landscaping in old districts of mountainous cities was analyzed,renovation design principles and basis were proposed. Pengshui County in Chongqing was taken for example to explore renovation design methods,overall concepts and relevant contents of the road landscaping in old districts of mountainous cities,so as to provide references for the renovation design of road landscaping in old districts of modern mountainous cities.     

Modal Analysis and Optimization of Shaft

For a ISA HEV,the transmission gear shaft dynamic model is established and the 3-D modal analysis is carfled out. Based on above work, the structure of the gear shaft is analysed, then the diameter of the gear shaft is taken as a design variable. With first order optimization,low inherent frequencies are optimized in order to avoid resonance and decrease NVH.