Research on Design Reference Period and Structural Design Method

2011 ◽  
Vol 368-373 ◽  
pp. 2364-2368
Author(s):  
Jia Nian He ◽  
Zhan Wang
Keyword(s):  
Structural Design ◽  
Reliability Index ◽  
Design Method ◽  
Structure Design ◽  
Reference Period ◽  
Building Structure ◽  
Safety Factors ◽  
Importance Factor ◽  
Partial Safety Factors

In structure design, for expressions with partial safety factors, partial safety factors and nominal value of loads are calculated based on the presupposition that the design reference period is 50 years. When the design reference period is not 50 years, it would cause unclear reliability of building structure by using expressions with partial safety factors following correlative codes yet. It may lead to hidden dangers in that way. In order to derive expressions with partial safety factors suitable for any design reference period, two useful methods are shown in this paper, modification of partial safety factors and modification of importance factor of structures. From results of analysis, we get the conclusions that it can assure the reliability index of the expression using the method of modification of partial safety factors, and the method of modification of importance factor of structures is very simple, but cannot assure the reliability index of the expression.

scholarly journals Structure design and reliability analysis of Al-Ti lugs

2021 ◽  
Vol 39 (1) ◽  
pp. 1-8
Author(s):  
Yunwen Feng ◽  
Jiale Zhang ◽  
Xiaofeng Xue ◽  
Xiaoping Zhong ◽  
Wei Xie
Keyword(s):  
Reliability Analysis ◽  
Structural Design ◽  
Design Principle ◽  
Load Transfer ◽  
Design Method ◽  
Static Strength ◽  
Structure Design ◽  
Safety Design ◽  
Design Requirements ◽  
Metal Materials

Aircraft lug joint is the key part of load transfer. In order to improve the safety of lug joint, on the premise of meeting the design requirements of static strength and fatigue, the composite connection lug structure design technology of different metal materials is proposed in this paper. Firstly, the damage safety design and life reliability analysis of the lug structure are studied theoretically. Secondly, based on the concept of damage safety design and the design principle of deformation coordination, the design method of composite connection lug with deformation coordination is proposed, and the thickness ratio of single ear is 0.8:1:0.8. Finally, the reliability of the composite lug is analyzed. The results show that the structural design scheme of aluminum-titanium composite ear piece can meet the requirements of static strength and damage tolerance, and compared with the conventional ear structure, the failure probability of structure mission life is greatly reduced when the weight of the composite connection lug is only increased by 4.9%. The proposed method can effectively guide the structural design of composite ear piece.

scholarly journals Discussion on Prefabricated Concrete Structure Design Method under BIM Technology

2020 ◽  
Vol 198 ◽  
pp. 03011
Author(s):  
Wang Hongyan ◽  
Zhang Zihong
Keyword(s):  
Life Cycle ◽  
Structural Design ◽  
Concrete Structure ◽  
Production Efficiency ◽  
Design Method ◽  
Collaborative Work ◽  
Structure Design ◽  
Building Information ◽  
Correct Understanding ◽  
Design Construction

BIM is a data tool used in various stages of design, construction and management. It can integrate different models of buildings and realize sharing and transmission during the life cycle of the project, ensuring that engineering technicians can access different building information with a correct understanding and real-time response, it lays a good foundation for different participants including design, construction and management to achieve collaborative work. It is very important whether it is to ensure production efficiency, save costs and shorten construction periods. For the newly emerging prefabricated buildings, their structural design will become more efficient, accurate and reasonable due to the introduction of BIM technology.

Partial Safety Factors Assessment of Pipes With a Circumferential Surface Flaw

2010 ◽  
Author(s):  
Hideo Machida ◽  
Hiromasa Chitose ◽  
Manabu Arakawa
Keyword(s):  
Fracture Resistance ◽  
Design Method ◽  
Limit State ◽  
Surface Flaw ◽  
Flaw Size ◽  
Material Strength ◽  
State Function ◽  
Safety Factors ◽  
Related Parameter ◽  
Partial Safety Factors

This paper describes the evaluation of partial safety factors (PSF’s) for parameters related to flaw evaluation of pipes which have a circumferential surface flaw, and proposes the important matter which should be pay attention in the setup of the safety factors used in flaw evaluation. PSF’s were evaluated considering randomness of flaw size, a fracture resistance curve (J-R curve) and applied loads using load and resistance factor design method (LRFD). The limit state function is expressed by fracture resistance (resistance-related parameter) and applied J integral (load-related parameter). The measure parameters in the reliability assessment are the flaw size and the J-R curve, and PSF’s of them are larger than those of applied loads. Since the material properties used in the flaw evaluation are generally set to the engineering lower limit of their variation (e.g., 95% lower confidence limit), variation of the flaw size is considered to have important role on flaw evaluation. Therefore, when setting up the safely factors used in Rules on Fitness-for-Service (FFS), it is necessary to take into consideration not only the influence of variation of loads or material strength but the influence of variation of flaw size.

scholarly journals GENERATIVE DESIGN OF STRUCTURAL STEEL JOINTS

2021 ◽  
Vol 12 (23) ◽  
pp. 22-32
Author(s):  
Anton Kralj ◽  
◽  
Davor Skejić ◽  
Keyword(s):  
Optimal Design ◽  
Design Process ◽  
Structural Design ◽  
Design Method ◽  
Steel Structures ◽  
Structure Design ◽  
Structural Behavior ◽  
Generative Design ◽  
Steel Joints ◽  
Technical Regulations

Structural project is based on technical regulations, structural codes, construction conditions, and client requirements. Through the structural design process, some important decisions that can significantly affect the final result must be implemented. The most important factor for optimal design is the reduction in material and overall work costs. Selecting appropriate joint configurations that can reduce the overall weight and work on the structure is critical. To examine a significant number of possible configurations and their effect on structural behavior, the generative design method (GDM) is used. In this study, software is custom developed, and a relevant example of generative joint structural design is provided. The methodology for the optimal joint and structure design is described comprehensively. The final results show that the GDM is an effective methodology for application in the design of steel structures.

scholarly journals Reliability-based calibration of Brazilian structural design codes used in the design of concrete structures

2019 ◽  
Vol 12 (6) ◽  
pp. 1288-1304
Author(s):  
W. C. SANTIAGO ◽  
H. M. KROETZ ◽  
A. T. BECK
Keyword(s):  
Structural Design ◽  
Concrete Structures ◽  
Transverse Reinforcement ◽  
Longitudinal Reinforcement ◽  
Design Codes ◽  
Safety Factors ◽  
Target Reliability Index ◽  
Live Loads ◽  
Effective Depth ◽  
Partial Safety Factors

Abstract This paper presents a reliability-based calibration of partial safety factors for Brazilian codes used in the design of concrete structures. The work is based on reliability theory, which allows an explicit representation of the uncertainties involved in terms of resistances and loads. Regarding the resistances, this study considers beams with concrete of five classes (C20, C30, C40, C50 and C60), three ratios between base and effective depth (0.25, 0.50 and 0.75), three longitudinal reinforcement ratios (ρmin, 0.5% and ρmax) and three transverse reinforcement ratios ( A s s m i n, 5 . A s s m i n and A s s m a x). In terms of loads, this work considers seven ratios between live loads and permanent loads (qn/gn), and seven ratios between wind loads and permanent loads (wn/gn). The study also adopts a single value for the target reliability index (βtarget = 3.0). Results show that the optimized set of partial safety factors leads to more uniform reliability for different design situations and load combinations.

The Differences between Section Rigidity and Member Stiffness and their Applications in Engineering Structural Design

2014 ◽  
Vol 971-973 ◽  
pp. 924-927
Author(s):  
Yan E Hao ◽  
Yong Qiang Lan
Keyword(s):  
Stress Analysis ◽  
Significant Role ◽  
Structural Design ◽  
Internal Force ◽  
Structure Design ◽  
Real Structure ◽  
Building Structure ◽  
Structural Force ◽  
Basic Concepts

Under the action of same loads, the sizes of deformation and internal force generated in the building structure are related to the inherent stiffness of member or structure itself. In structure design, these two basic concepts of section rigidity and member stiffness play a significant role in stress analysis of member or structure. This article summarizes the application of section rigidity and member stiffness which are often used in structural design by contrasting the definition and calculation of section rigidity with those of member stiffness, which can help the designers to understand the two concept of “rigidity” well and utilize them reasonably in real structure designs, and make the designed structural force conform to relative codes and regulations.

Target Reliability Index for Load and Resistance Factor Design of Class 2 Carbon Steel Pipes

2017 ◽  
Author(s):  
Kleio Avrithi ◽  
Ramiro Mendoza
Keyword(s):  
Carbon Steel ◽  
Internal Pressure ◽  
Reliability Index ◽  
Safety Margin ◽  
Resistance Factor ◽  
Safety Factors ◽  
Target Reliability Index ◽  
Partial Safety Factors ◽  
Factor Design ◽  
Load And Resistance Factor

The use of the Load and Resistance Factor Design (LRFD) for Class 2 nuclear piping can be an alternative of the traditional Allowable Stress Design (ASD) method currently used in the ASME Boiler Pressure Vessel Code, Section III, Div. 1 providing the benefit of a known and consistent reliability for the designed piping. The design uncertainties and the necessary safety margin are evaluated for each equation for all service levels by considering the applied loads (e.g., earthquake, deadweight, internal pressure, etc.) and the resistance of steel, in the form of either the yield or ultimate strength, as separate variables described by their mean value, distribution, and coefficient of variation. The procedure yields different partial safety factors for each load and the resistance in opposition to the one safety factor used in each of the ASD equations of the Code. Although LRFD equations have been developed in the past, a range of possible partial safety factors were assigned to the variables, corresponding to different levels of reliability. This paper discusses the method used, namely calibration, for achieving same reliability as in the Code equations, and the progress made to assess a minimum target reliability index or else acceptable probability of failure for the LRFD equations that consider the earthquake load for pressurized pipes as well as the design for internal pressure for Class 2 nuclear pipes made of carbon steel.

scholarly journals STRUCTURE DESIGN AND STRENGTH ANALYSIS OF CHILD SEAT FOR MOTORCYCLE

2021 ◽  
Vol 7 (1) ◽  
pp. 38-45
Author(s):  
Dara Ginanti
Keyword(s):  
Structural Design ◽  
Mass Production ◽  
Safety Issue ◽  
Static Condition ◽  
Structure Design ◽  
Strength Analysis ◽  
Safety Factors

Many people in Indonesia are having a serious safety issue in bringing their children to ride a motorcycle. A proper child seat is needed to guarantee the safety of the child and the rider itself. In this paper, the structural design of a child seat for a motorcycle using a spring-damper system is presented as a reference to build a safe and comfortable seat. Analysis of the static condition, dynamics condition, buckling, and also fatigue is also done calculated and it is resulting in some safety factors. The safety factors are found to be in the range of 1-11. Based on that analysis result, the conclusion that can be highlighted is that the child seat is safe. Due to some concern related to safety, this innovation is recommended to be applied for mass production, furthermore, improvement, and optimization is also possible for this design.

scholarly journals PROPOSAL FOR THE STRUCTURAL DESIGN METHOD OF A SUSTAINABLE BUILDING STRUCTURE SYSTEM

2009 ◽  
Vol 74 (640) ◽  
pp. 1179-1185 ◽  
Author(s):  
Yukiko SHIMA ◽  
Junya KOGAWA ◽  
Takashi KATOH ◽  
Chikanori MAEDA ◽  
Mamoru IWATA
Keyword(s):  
Structural Design ◽  
Design Method ◽  
Building Structure ◽  
Sustainable Building ◽  
Structure System

Application of Ejector Technology to the Efficient Exploitation in the Low-Pressure Gas Well

2013 ◽  
Vol 433-435 ◽  
pp. 2196-2202
Author(s):  
Xue Yuan Long ◽  
Zhi Jun Li ◽  
Yuan Tian
Keyword(s):  
Numerical Simulation ◽  
Design Method ◽  
Field Tests ◽  
Low Pressure ◽  
Structure Design ◽  
Building Structure ◽  
Gas Wells ◽  
Gas Well ◽  
The Cost ◽  
Dynamics Method

According to the research status of spray and drainage technology at home and abroad, based on the basic design of the ejector, this paper designs the ejector geometry, and do numerical simulation and analysis for ejection and combination flow field inside the ejector by using computational fluid dynamics method, building structure design of ejectors with pressure-gain for low-pressure gas wells. Verified by numerical simulation and field tests, the results showed that ejector design method is reliable. The operation of the device at the scene is safe and stable, achieving such goals as using energy from high-pressure wells to drive the low-pressure wells to work stably; delaying pressurization and exploitation for gas wells, reducing the cost of production and management. Field experiment is very effective, providing a new channel for us to increase the pressure of low-pressure gas wells and exploit them.

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