Load-Effect Separation of a Large-Span Prestressed Structure Based on an Enhanced EEMD-ICA Methodology

2022 ◽  
Vol 148 (3) ◽  
Author(s):  
Yaozhi Luo ◽  
Wenwei Fu ◽  
Hua-Ping Wan ◽  
Yanbin Shen
Keyword(s):  
Load Effect ◽  
Large Span

Study on a Large-Span Steel Truss Roof Isolation Bearings for Wind Load Effect Isolation Effect

2013 ◽  
Vol 405-408 ◽  
pp. 1022-1027
Author(s):  
Zi Fen Fang ◽  
Zhi Qiang Zhang ◽  
Fei Liu
Keyword(s):  
Financial Services ◽  
Base Isolation ◽  
Wind Load ◽  
Isolation Effect ◽  
Load Effect ◽  
Large Span ◽  
Roof Structure ◽  
Rubber Bearing ◽  
Steel Truss ◽  
Load Effects

The isolation of large-span Steel Truss Roof structure is developed on the basis of base isolation. The isolation of large-span Steel Truss Roof structure is to limit the transmission of wind load effect to the substructure. Based on the engineering background, we mainly discuss using rubber bearing isolation structure wind load effects. This paper will explains and demonstrates the isolation mechanism of Large-span Steel Truss Structure,and than test and verify isolation effect by Calculating through the analysis of wind tunnel tests conducted on the Yancheng financial services center, which the steel truss roof isolation bearings for wind load effect isolation effect.

The Experimental Analysis of the Nonlinear Effects of Live Load of E-Dong Yangtze River Highway Bridge

2014 ◽  
Vol 587-589 ◽  
pp. 1672-1679
Author(s):  
Hui Ling Chen
Keyword(s):  
Geometric Nonlinearity ◽  
Yangtze River ◽  
Nonlinear Effects ◽  
Highway Bridge ◽  
Live Load ◽  
Load Effect ◽  
Large Span ◽  
Cable Stayed Bridge ◽  
Long Span ◽  
Actual Response

E-dong Yangtze River Highway Bridge is a compound double Tower Double Suspension Cable stayed bridge with a main-span of 926m. it has very distinctive geometric nonlinearity, which features as a long span, a high Tower, a soft construction, etc. in order to analyze how the geometric nonlinearity will affect the live load effect of large-span cable stayed bridge, we adopted the experimental results of the static experiments of the E-dong bridge to do a comparative analysis, during which all the calculation was based on the limited Factor theory. And the results showed that, the nonlinear results fit much better with the actual response of large-span cable stayed bridge, while the linear results produced a big difference.

Translucent Glass Roofs For Large-Span Coverings

2019 ◽  
pp. 23-28
Keyword(s):  
Warm Season ◽  
Natural Light ◽  
Labor Costs ◽  
Main Bearing ◽  
Large Span ◽  
Glass Panels ◽  
Technical Properties ◽  
Internal Volume ◽  
Basic Approaches ◽  
Smoke Removal

The article deals with the issues of glass use in the enclosing structures of large-span coverings, which have such advantages as ensuring the penetration of natural light, tightness, minimum labor costs for repair and maintenance. Design shortcomings: the high cost, the need for protection of the internal volume against the penetrating sun rays in the warm season (hothouse effect); arrangement of devices for operation of a roof. The key technical properties and characteristics of glass panels and pane-glass sets, constructive decisions, including interface to the main bearing structures of a large-span covering are given. Peculiarities of their design with due regard for ventilation and smoke removal, a drainage of condensate, ways of fight against frosting and snow drifts on the roof are reflected. Features of the account of loadings, the basic approaches to their calculation are considered. Various design solutions for the spatial metal trussed systems with the original nodal connections are presented. Information on modern solutions of translucent roofs using glass for large-span coverings is given.

Live-Load Girder Distribution Factors for Bridges Subjected to Wide Trucks

2000 ◽  
Vol 1696 (1) ◽  
pp. 144-149 ◽  
Author(s):  
Sami W. Tabsh ◽  
Muna Tabatabai
Keyword(s):  
Finite Element ◽  
The United States ◽  
Live Load ◽  
Wheel Load ◽  
Element Analysis ◽  
Load Effect ◽  
Design Specifications ◽  
Girder Bridges ◽  
Girder Distribution Factors ◽  
Modification Factor

An important problem facing engineers and officials in the United States is the constraint imposed on transportation due to limitations of bridges. These limitations typically constrain vehicles to minimum heights and widths, to minimum and maximum lengths, and to a maximum allowable weight. However, with current demands of society and industry, there are times when a truck must carry a load that exceeds the size and weight of the legal limit. In this situation, the trucking company requests from the state departments of transportation an overload permit. For a truck with a wheel gauge larger than 1.8 m (6 ft), the process of issuing a permit for an overload truck requires a tremendous amount of engineering efforts. This is because the wheel load girder distribution factors (GDFs) in the design specifications cannot be used to estimate the live-load effect in the girders. In some cases, an expensive and time-consuming finite element analysis may be needed to check the safety of the structure. In this study, the finite element method is used to develop a modification factor for the GDF in AASHTO’s LRFD Bridge Design Specifications to account for oversized trucks with a wheel gauge larger than 1.8 m. To develop this factor, nine bridges were considered with various numbers of girders, span lengths, girder spacings, and deck slab thicknesses. The results indicated that use of the proposed modification factor with the GDF in the design specifications can help increase the allowable load on slab-on-girder bridges.

scholarly journals Modeling and Performance Optimization of an Irreversible Two-Stage Combined Thermal Brownian Heat Engine

Entropy ◽  
2021 ◽  
Vol 23 (4) ◽  
pp. 419
Author(s):  
Congzheng Qi ◽  
Zemin Ding ◽  
Lingen Chen ◽  
Yanlin Ge ◽  
Huijun Feng
Keyword(s):  
Power Output ◽  
Performance Optimization ◽  
External Load ◽  
Thermal Contact ◽  
Heat Engine ◽  
Design Parameters ◽  
Load Effect ◽  
Heat Engines ◽  
Heat Leakage ◽  
Steady Current

Based on finite time thermodynamics, an irreversible combined thermal Brownian heat engine model is established in this paper. The model consists of two thermal Brownian heat engines which are operating in tandem with thermal contact with three heat reservoirs. The rates of heat transfer are finite between the heat engine and the reservoir. Considering the heat leakage and the losses caused by kinetic energy change of particles, the formulas of steady current, power output and efficiency are derived. The power output and efficiency of combined heat engine are smaller than that of single heat engine operating between reservoirs with same temperatures. When the potential filed is free from external load, the effects of asymmetry of the potential, barrier height and heat leakage on the performance of the combined heat engine are analyzed. When the potential field is free from external load, the effects of basic design parameters on the performance of the combined heat engine are analyzed. The optimal power and efficiency are obtained by optimizing the barrier heights of two heat engines. The optimal working regions are obtained. There is optimal temperature ratio which maximize the overall power output or efficiency. When the potential filed is subjected to external load, effect of external load is analyzed. The steady current decreases versus external load; the power output and efficiency are monotonically increasing versus external load.

scholarly journals Influences of Residual Stress, Surface Roughness and Peak-Load on Micro-Cracking: Sensitivity Analysis

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 320
Author(s):  
Jairan Nafar Dastgerdi ◽  
Fariborz Sheibanian ◽  
Heikki Remes ◽  
Hossein Hosseini Toudeshky
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Crack Formation ◽  
Peak Load ◽  
Crack Size ◽  
Effective Parameters ◽  
Load Range ◽  
Load Effect ◽  
Damage Initiation ◽  
Load Conditions

This paper provides further understanding of the peak load effect on micro-crack formation and residual stress relaxation. Comprehensive numerical simulations using the finite element method are applied to simultaneously take into account the effect of the surface roughness and residual stresses on the crack formation in sandblasted S690 high-strength steel surface under peak load conditions. A ductile fracture criterion is introduced for the prediction of damage initiation and evolution. This study specifically investigates the influences of compressive peak load, effective parameters on fracture locus, surface roughness, and residual stress on damage mechanism and formed crack size. The results indicate that under peak load conditions, surface roughness has a far more important influence on micro-crack formation than residual stress. Moreover, it is shown that the effect of peak load range on damage formation and crack size is significantly higher than the influence of residual stress. It is found that the crack size develops exponentially with increasing peak load magnitudes.

Buckling characteristics of cut-out borne composite stiffened hyperbolic paraboloid shell panel

2021 ◽  
pp. 146442072110058
Author(s):  
Sarmila Sahoo
Keyword(s):  
Finite Element ◽  
Orientation Angle ◽  
Buckling Load ◽  
Benchmark Problems ◽  
Hyperbolic Paraboloid ◽  
Element Analysis ◽  
Load Effect ◽  
Global Buckling ◽  
Fiber Orientation Angle ◽  
Shell Panel

The present study investigates buckling characteristics of cut-out borne stiffened hyperbolic paraboloid shell panel made of laminated composites using finite element analysis to evaluate the governing differential equations of global buckling of the structure. The finite element code is validated by solving benchmark problems from literature. Different parametric variations are studied to find the optimum panel buckling load. Laminations, boundary conditions, depth of stiffener and arrangement of stiffeners are found to influence the panel buckling load. Effect of different parameters like cut-out size, shell width to thickness ratio, degree of orthotropy and fiber orientation angle of the composite layers on buckling load are also studied. Parametric and comparative studies are conducted to analyze the buckling strength of composite hyperbolic paraboloid shell panel with cut-out.

scholarly journals Comparison of reliability evaluation methods between China and Canada standards for wood structures featuring duration of load

2020 ◽  
Vol 66 (1) ◽  
Author(s):  
Qiongyao Wu ◽  
Shuang Niu ◽  
Enchun Zhu
Keyword(s):  
Reliability Analysis ◽  
Analysis Method ◽  
Safety Level ◽  
Wood Structures ◽  
Load Effect ◽  
Key Factor ◽  
Live Loads ◽  
High Level ◽  
Partial Factor ◽  
Duration Of Load

Abstract Duration of load (DOL) is a key factor in design of wood structures, which makes the reliability analysis of wood structures more complicated. The importance of DOL is widely recognized, yet the methods and models through which it is incorporated into design codes vary substantially by country/region. Few investigations of the effect of different model assumptions of DOL and other random variables on the results of reliability analysis of wood structures can be found. In this paper, comparisons are made on the reliability analysis methods that underlie the China and the Canada standards for design of wood structures. Main characteristics of these two methods, especially the way how DOL is treated are investigated. Reliability analysis was carried out with the two methods employing the same set of material properties and load parameters. The resulted relationships between reliability index β and resistance partial factor γR* (the β–γR* curves) for four load combinations are compared to study the safety level indicated by the two methods. The comparison shows that the damage accumulation model (Foschi–Yao model) in the Canada analysis method is highly dependent on the type and duration of load, resulting in more conservative design than the China analysis method in loading cases dominated by dead load, but less conservative design in cases of high level of live loads. The characteristics of the load effect term of the performance function are also found to make considerable difference in reliability levels between the two methods. This study aims to provide references for researchers and standard developers in the field of wood structures.

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