scholarly journals Assessment of Accidental Torsion in Building Structures Using Static and Dynamic Analysis Procedures

2020 ◽  
Vol 10 (16) ◽  
pp. 5509 ◽  
Author(s):  
Osama Ahmed Mohamed ◽  
Mohamed Sherif Mehana

This article presents the findings of a study on assessment of the increase in building’s response due to accidental torsion when subjected to seismic forces. Critical stiffness and geometrical parameters that define buildings torsional response are examined including: (1) the ratio, Ω, between uncoupled torsional frequency ωθ to uncoupled translation frequencies in the direction of ground motion ωx or ωy, (2) floor plan aspect ratio, b/r, which is a function of the floor dimension and radius of gyration. The increased response is assessed on symmetric multi-storey buildings using both static and dynamic analysis methods specified by ASCE-7 and considering parameters affecting the torsional response. It was concluded that static and dynamic analysis procedures predict different accidental torsion responses. Static analysis based on the Equivalent Lateral Force (ELF) method predicts more conservative accidental torsions responses for flexible structures with Ω < 0.7~0.80, while the responses are less conservative for stiffer buildings. The conservativism in static analysis method is attributed to the response amplification factor, Ax. Floor plans and their lateral support system having frequency ratio Ω = 1 will also have a torsional radius equal to radius of gyration, and will experience drop in torsional response relative to more torsionally flexible buildings. This article presents a procedure to overcome the shortcomings of static and dynamic analysis procedures in terms of estimating accidental torsion response of symmetric building structures.

2017 ◽  
Vol 11 (3) ◽  
pp. 15-28 ◽  
Author(s):  
Anjali Kumawat ◽  
Anil Kumar Sharma ◽  
Sunita Kumawat

Android based Smartphones are nowadays getting more popular. While using Smartphone, user is always concerned about security and malicious attacks, cryptographic vulnerability of the applications. With increase in the number of Android mobiles, Android malwares are also increasing very rapidly. So the authors have proposed the “Identification of cryptographic vulnerability and malware detection in Android” system. They have designed a user friendly android application, through which user and developer can easily test the application whether it is benign or vulnerable. The application will be tested firstly using static analysis and then the dynamic analysis will be carried out. The authors have implemented static and dynamic analysis of android application for vulnerable and malicious app detection. They have also created a web page. User can either use the application or the web page.


2014 ◽  
Vol 670-671 ◽  
pp. 892-895
Author(s):  
An Ning Zhang ◽  
Yu Ming Gu

This paper studied the difference between the static analysis and dynamic analysis on the mobile refuge chamber. The structure strength static analysis of KJYF96/8 mobile refuge chamber was made by the finite element software SolidWorks Simulation and the stress cloud chart and the displacement cloud chart were obtained. The corresponding relation between the dynamic analysis result and the static analysis result was obtained based on the comparison with the result of the dynamic analysis. The results indicate that the values of the max stress and displacement by static analysis with a uniform external pressure of the dynamic pressure peak value are greater than those by dynamic analysis. And the weighting method of static analysis can be used in the coal mine mobile refuge chamber structure design process instead of dynamic analysis.


Author(s):  
Arati Avinash Sabale

Vibration of ground is the main cause of earthquake damage to building structures. There are many factors responsible for the strength of earthquake shaking at a site including the earthquake's magnitude, the site's proximity to the fault, the local geology, and the soil type. The natural disasters have been fast recurring all over the world causing great concern and damage to man and their properties. Among these disasters Earthquake is an endogenous natural disaster, which occurs suddenly without any warning. The vast devastation of engineering systems and facilities during the past earthquakes has exposed serious deficiencies in the prevalent design and construction. Shear wall is one of the most commonly used lateral load resisting in high rise buildings. Shear wall can be used to simultaneously resist large horizontal load and support gravity load. In the study, one tall RCC building of 13 stories is assumed to be situated in seismic zone V is analysed using two methods (Static and Dynamic Analysis). The share walls are taken at different position of building. The comparison of the different shear wall models is studied in this work against the different parameters like time period, bending moment, shear force, storey drift, displacement


Author(s):  
Zhenhui Liu ◽  
Ragnar Igland ◽  
Sindre Bruaseth ◽  
Luca Ercoli-Malacari

Abstract A rigid subsea spool is used to connect the riser of a jacket platform to oil export pipeline in Johan Sverdrup oil field. The location is within the lifting zones of the platform. Consequently, the dropped object hazard has potential high risk and needs to be checked. This paper presents a numerical model on accessing the structural dynamics of subsea spool under the dropped container impact loads by using de-coupled local and global model. The impact impulse was obtained from local impact analysis by Abaqus Explicit solver, in which deformations from container and pipeline are both captured. The global model was built by using inhouse program utilizing ANSYS APDL macros. A simple input file is only needed for end users. The nonlinear pipe and soil interaction is included in a simplified manner. The model comprises of static and dynamic analysis parts. The static analysis captures the in-place configuration and the functional loads. The dynamic analysis is a restart with inherited stress state from static analysis. The impact impulse was applied by point loads in a certain time range. The nonlinear soil stiffness was approached by spring elements (compression only). The dynamic analysis was done in a longer time, ensuring to capture any dynamic effects. The interface loads at the riser stick-out and riser anchor are both extracted and discussed. Concluding remarks have been made accordingly.


Information ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 326 ◽  
Author(s):  
Amr Amin ◽  
Amgad Eldessouki ◽  
Menna Tullah Magdy ◽  
Nouran Abdeen ◽  
Hanan Hindy ◽  
...  

The security of mobile applications has become a major research field which is associated with a lot of challenges. The high rate of developing mobile applications has resulted in less secure applications. This is due to what is called the “rush to release” as defined by Ponemon Institute. Security testing—which is considered one of the main phases of the development life cycle—is either not performed or given minimal time; hence, there is a need for security testing automation. One of the techniques used is Automated Vulnerability Detection. Vulnerability detection is one of the security tests that aims at pinpointing potential security leaks. Fixing those leaks results in protecting smart-phones and tablet mobile device users against attacks. This paper focuses on building a hybrid approach of static and dynamic analysis for detecting the vulnerabilities of Android applications. This approach is capsuled in a usable platform (web application) to make it easy to use for both public users and professional developers. Static analysis, on one hand, performs code analysis. It does not require running the application to detect vulnerabilities. Dynamic analysis, on the other hand, detects the vulnerabilities that are dependent on the run-time behaviour of the application and cannot be detected using static analysis. The model is evaluated against different applications with different security vulnerabilities. Compared with other detection platforms, our model detects information leaks as well as insecure network requests alongside other commonly detected flaws that harm users’ privacy. The code is available through a GitHub repository for public contribution.


Author(s):  
Anjali Kumawat ◽  
Anil Kumar Sharma ◽  
Sunita Kumawat

Android based Smartphones are nowadays getting more popular. While using Smartphone, user is always concerned about security and malicious attacks, cryptographic vulnerability of the applications. With increase in the number of Android mobiles, Android malwares are also increasing very rapidly. So the authors have proposed the “Identification of cryptographic vulnerability and malware detection in Android” system. They have designed a user friendly android application, through which user and developer can easily test the application whether it is benign or vulnerable. The application will be tested firstly using static analysis and then the dynamic analysis will be carried out. The authors have implemented static and dynamic analysis of android application for vulnerable and malicious app detection. They have also created a web page. User can either use the application or the web page.


2014 ◽  
Vol 19 (3) ◽  
pp. 609-619
Author(s):  
C. Kundera ◽  
V.A. Martsinkovsky

Abstract This part of the work presents the design and static analysis of an impeller for a single-stage pump. The impeller is directly connected with a balancing device. The impeller needs to have a properly designed system of longitudinal and lateral clearances on both sides. With the simplifying assumptions concerning the flow and distribution of pressure in the longitudinal and lateral clearances, the static analysis involved deriving relationships between the impeller geometry and the basic performance parameters of the pump. A numerical example was used to show the calculation procedure of static characteristics for the predetermined parameters


1983 ◽  
Vol 4 (2) ◽  
pp. 233-246
Author(s):  
Wang Xing-xiang ◽  
Che Wei-yi ◽  
Yu Yong-sheng

2012 ◽  
Vol 193-194 ◽  
pp. 639-642 ◽  
Author(s):  
Chang Zheng Chen ◽  
Ping Ping Pan ◽  
Shi Wei Zhang ◽  
Meng Qiang

This paper presents static and dynamic analysis of wind turbine towers which is supporting a 1.5MW wind turbine based on the theory of FEM. In static analysis, the modal frequencies of the towers are analyzed without wind load. In dynamic analysis, by the fluid-coupling theory, the dynamic effect of wind loads on the towers is calculated. It can be concluded that the main errors under the different load situations is caused by the impact of fluid structure coupling.


2021 ◽  
Vol 1201 (1) ◽  
pp. 012049
Author(s):  
Z Liu ◽  
R Igland ◽  
S Bruaseth

Abstract Subsea riser tube and spool is often used together to connect the riser of jacket to flowline or pipeline. Due to its limited size (less than 200 m), the location is within the lifting zones of the platform. Consequently, the dropped object hazard has potential high risk and needs to be checked. This paper presents a numerical study on accessing the structural dynamics of a subsea riser connection under the dropped container impact loads. De-coupled local and global models were established. The impact impulse was obtained from local impact analysis by Abaqus Explicit solver, in which deformations from container and pipeline are both captured. The impact energy level is in line with the risk assessment. The global model was built by ANSYS APDL macros. A simple input file is only needed for end users. The nonlinear pipe and soil interaction are included in a simplified manner. The model comprises of static and dynamic analysis parts. The static analysis captures the in-place configuration and the functional loads. The dynamic analysis is a restart with inherited stress state from static analysis. The impact impulse was applied by point loads in a certain time range. The nonlinear soil stiffness was approached by spring elements (compression only). The dynamic analysis was done in a longer time, ensuring to capture any dynamic effects. The interface loads at the riser stick-out and riser anchor are both extracted and discussed. It is shown that present structure design can withstand the dropped loads at the input energy level.


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