The Study about Anti-Seismic Structures Stirrup Construction Blanking Length Theory Calculation

2014 ◽  
Vol 580-583 ◽  
pp. 2277-2280
Author(s):  
Hui Ling Li ◽  
Xu Xiang Cui ◽  
Yu Han Zhao

According to the new norm’s requirements and regulations for stirrup and related construction , deducing the theoretical calculation formula of stirrup blanking length of anti-seismic component in different levels. And analyzing it and the three empirical calculation methods comparatively, to find out the application conditions and scope of the empirical calculation method.

2011 ◽  
Vol 219-220 ◽  
pp. 1621-1624
Author(s):  
Guo Qi Li ◽  
Si Jing Liu

For the multi-attribute characteristics of scale, quantity, service radius and target of service in city logistics facilities,this paper considered the similar phenomena between city logistics facilities caused by the interaction of different social and economic attributes. Based on the analysis of the similarity degree calculation methods in computer science and mechanical engineering, it proposed two calculation methods of similarity degree in city logistics facilities. The qualitative and quantitative attributes were considered separately in the first method, the quantitative attributes were disposed by triangular fuzzy number.The similarity dimension was introduced as the basis of the similarity degree calculation in the second method. A merge processing method was used to incorporate all similar characteristics of every similarity dimension and a similarity calculation formula was deduced from the theory of similarity.


2018 ◽  
Vol 232 ◽  
pp. 02005
Author(s):  
Bin Li ◽  
Song Guo ◽  
Wei Li ◽  
Deman Zhang ◽  
Nei Wang

Comprehensive characteristics of a pneumatic underwater launching system were analyzed and the simulation was carried out by simulink. The components of the pneumatic underwater launching system were introduced, and the theoretical calculation formula for the system was derived. A rated pressure of 3.5MPa and 5MPa was offered in the numerical work. Analyses in different piston height show good behaviors: Proper increase of piston-initial accumulator pressure is beneficial to reduce hydrodynamic noise, choose the appropriate pressure of accumulator. The hydrodynamic noise of the system can be significantly reduced by optimizing the structure of the double-acting cylinder, increasing the height of the piston and improving the structure of the piston.


Aerospace ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 61
Author(s):  
Dominik Eisenhut ◽  
Nicolas Moebs ◽  
Evert Windels ◽  
Dominique Bergmann ◽  
Ingmar Geiß ◽  
...  

Recently, the new Green Deal policy initiative was presented by the European Union. The EU aims to achieve a sustainable future and be the first climate-neutral continent by 2050. It targets all of the continent’s industries, meaning aviation must contribute to these changes as well. By employing a systems engineering approach, this high-level task can be split into different levels to get from the vision to the relevant system or product itself. Part of this iterative process involves the aircraft requirements, which make the goals more achievable on the system level and allow validation of whether the designed systems fulfill these requirements. Within this work, the top-level aircraft requirements (TLARs) for a hybrid-electric regional aircraft for up to 50 passengers are presented. Apart from performance requirements, other requirements, like environmental ones, are also included. To check whether these requirements are fulfilled, different reference missions were defined which challenge various extremes within the requirements. Furthermore, figures of merit are established, providing a way of validating and comparing different aircraft designs. The modular structure of these aircraft designs ensures the possibility of evaluating different architectures and adapting these figures if necessary. Moreover, different criteria can be accounted for, or their calculation methods or weighting can be changed.


Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1303
Author(s):  
Chenghua Shi ◽  
Xiaohe Sun ◽  
Shengli Liu ◽  
Chengyong Cao ◽  
Linghui Liu ◽  
...  

At present, jet-grouted horizontal waterproof curtain reinforcement has become an essential method for deep foundation pit groundwater control. However, there is still a lack of an effective theoretical calculation method for horizontal waterproof curtain reinforcement, and there is little research on the seepage laws of foundation pits under different horizontal waterproof curtain conditions. Based on Darcy’s seepage theory, theoretical analysis models of deep foundation pit seepage were established considering the effect of a horizontal curtain in a highly permeable formation. Through the established models, the calculation method of the water inflow and the water pressure under the condition of a horizontal curtain was derived. Then through indoor tests, the reliability of the theoretical calculation method was verified. Furthermore, the established theoretical calculation method is used to analyze the influence of various factors on the water inflow and the water pressure, such as the ratio of hydraulic conductivity of the horizontal curtain to surrounding soil, thickness, and reinforcement position of the horizontal curtain. It is found that the hydraulic conductivity ratio has the most significant influence on the seepage characteristics of the foundation pit. Finally, the design method was applied to an example of the horizontal waterproof curtain of the foundation pit, which is located at Juyuanzhou Station in Fuzhou (China). The water inflow per unit area is 0.36 m3/d in the foundation pit, and this implies that the design method of the horizontal waterproof curtain applied for the excavation case is good and meets the requirements of design and safety.


2017 ◽  
Vol 865 ◽  
pp. 247-252
Author(s):  
Gui Tao Du

Because of the added mass, the aerodynamic drag of the automobile will increase obviously when accelerating in the still air. In this paper, it firstly gave the definition of the added mass, and presented that there was little research on the calculation of the added mass of automobile. Then through the analysis of the theoretical calculation method for the added mass, it pointed out that, for the added mass of the car-body with a complex shape, there was much difficulty in the theoretical calculation. Alternatively, a numerical calculation method for the added mass of car-body was derived. The simulation model adopted the Ahmed body and the corresponding verification experiment was completed in the Tongji Automotive Wind Tunnel center. The results indicate that the added mass is a constant which is only dependent on the body-shape. For the model investigated, the added mass is 0.0052kg that is approximately equal to the air displaced by the car-body. As the body accelerates to 4m/s2, the aerodynamic drag is increased by 1.89% because of added mass. Therefore, it needs to pay more attention to the impact that the added mass has on the dynamic performance of vehicle when proceeding the aerodynamic designs (especially for the high power performance vehicles). Meanwhile, it still makes a correction to the conventional aerodynamic drag formula. This paper also demonstrates that, with the analysis of the flow-field of car-body, the added mass essentially stems from the additionally work done by the car-body to increase the kinetic energy of external fluid as it speeds up.


Author(s):  
Reignard Tan ◽  
Terje Kanstad ◽  
Mette R. Geiker ◽  
Max A. N. Hendriks

<p>Motivated by the establishment of a Ferry-Free E39 coastal highway route, crack width calculation methods for design of large-scale concrete structures are discussed. It is argued that the current semi-empirical formulas recommended by Eurocode 2 is inconsistent and overly conservative for cross sections with large bar diameters and covers. A suggestion to formulating a more consistent crack width calculation method is given.</p>


2021 ◽  
Author(s):  
David Earl Cain ◽  
Keith Albert Klopfenstein ◽  
James Robert McMullan

Abstract A decommissioning and abandonment requirement to shear 9 5/8-inch casing in certain circumstances with a 13 5/8-inch × 10,000 psi rated working pressure, RWP, Shear RAM type blowout preventer, BOP, resulted in a need to develop a novel casing shear device and shear calculation method. Results of shear testing, future engineering planning guidance, the new shear calculation method, and comparison to legacy technology are included in this paper. Interaction with the end user to understand requirements, a five-step problem solving procedure, a basis of design process, materials justification, verification analysis, validation testing, and describing an improved shear operator force/pressure calculation are all described. Shear larger casing in the required and restrictive RAM BOP and well bore presented a problematic challenge. Equally, tubular fish size was required to support fishing extraction operations following shear. Validation test results exceeded requirements and resulted in the need for a new approach to the shear calculation method. The novel shear RAM geometry was developed utilizing shear calculation methods which were based on legacy considerations. API 16A shear validation procedures and two legacy shear calculation methods where employed. Shear calculations are used to anticipate the RAM BOP operator pressures required to shear a specific tubular. The larger than historically allowed casing size to be sheared in a 13 5/8-inch × 10,000 psi RAM BOP meant higher operator pressures were anticipated for each operator option. A Novel shear RAM geometry was developed as a design intent to lower shear force/pressure. There was an observation during validation testing that the geometry exceeded expectations to lower shear pressure significantly. This observation led to a conclusion that an improved shear calculation method was required for this application. This novel calculation method description / statistical treatment, test results, RAM design methods, and tabular shear engineering planning information are included in this paper. One additional requirement of the shear RAM geometry was to provide an upper and lower fish deformed surface which could be easily retrieved thru the 13 5/8-inch BOP bore. An additional observation was that the fish width requirement was achieved. The novel shear calculation method allows an engineer to precisely plan for bonnet actuation pressures when larger casing is sheared. The precise calculation of shear force/pressure also assists with BOP operator size and type selection. The engineer will gain casing size versus shear pressure for specific operator options in tabular format. Planners will gain insight into tubular fish deformation estimation allowing mitigation of tubular extraction risk during operations planning.


Author(s):  
Pavlo Krainskyi ◽  
Pavlo Vegera ◽  
Roman Khmil ◽  
Zinoviy Blikharskyy

2012 ◽  
Vol 166-169 ◽  
pp. 610-615
Author(s):  
Yong Yang ◽  
Kang An ◽  
Su Sheng Zeng ◽  
Jian Yang Xue

Based on the experiment results of five plain steel plate-light weight concrete hollow deck specimens, the design methods of the composite decks which mainly including the calculation method of the bearing capacity and calculation method of the flexural rigidity were introduced. In the paper, the bearing capacity and flexural rigidity of the composite at two orthogonal directions, which including the direction parallel to the pipes and the direction perpendicular to the pipes, were both introduced. The calculation results of the bearing capacity and middle-span deflection were in good agreement with those of the experimental results, and in the return calculation methods were verified. Therefore, the design methods and calculation methods were useful to the design of this new type composite deck.


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