New Seismic Pushover Procedures using either Floor Enforced-Displacements or Inelastic Dynamic Eccentricities on Irregular Single-Storey R/C Buildings
Triantafyllos
Makarios
Professor (Asst), Institute of Structural Analysis and Dynamics of Structure, School of Civil Engineering, Aristotle University of Thessaloniki, GR-54124, Greece
author
Athanasios
Bakalis
Dipl. Eng. MSc, Institute of Structural Analysis and Dynamics of Structure, School of Civil Engineering, Aristotle University of Thessaloniki, GR-54124, Greece
author
text
article
2019
eng
A numerical example of a torsionally-flexible, R/C, asymmetric single-storey building is presented here to clarify in detail the step by step application of two new documented pushover procedures on single-storey R/C buildings. In order to fully consider the coupling between torsional and translational vibrations of the floor-diaphragm under seismic action, the first pushover procedure uses floor enforced-displacements, while the second one uses lateral static floor forces applied with suitable inelastic design eccentricities (inelastic dynamic plus accidental ones) relative to CM. Both pushover procedures referred to the “Capable Near Collapse Principal reference system ” of the single-storey building. The floor enforced-translations/rotation and the appropriate inelastic dynamic eccentricities used in the two proposed procedures derive from extensive parametric analysis and are given by tables or suitable equations. The evaluation of both procedures relative to the results of non-linear response history analysis shows that both procedures predict with safety the in-plan displacements of the building.
Computational Engineering and Physical Modeling
Pouyan Press
2588-6959
2
v.
4
no.
2019
1
23
https://www.jcepm.com/article_104426_b216c108238ebcec663b473f3412ebe0.pdf
dx.doi.org/10.22115/cepm.2020.216973.1082
EN 338 Strength Characterization and Grading of Igba (Rhizophora Racemosa) and Adere (Syzgium Guineense) Timbers for Structural Applications
Babatunde
Ibitolu
Department of Civil Engineering, University of Ilorin, Ilorin, Nigeria
author
Abdullahi
Jimoh
Department of Civil Engineering, University of Ilorin, Ilorin, Nigeria
author
Olawale
Babatunde
Department of Civil Engineering, University of Ilorin, Ilorin, Nigeria
author
text
article
2019
eng
The paper characterizes two potential timbers grown in Nigeria according to EN338 (2009) timber strength classification. The timbers namely Igba (Rhizophora racemosa) and Adere (Syzgium guineense) were obtained in Kwara state in the North-central part of Nigeria. Physical and Mechanical properties of timber species were obtained in accordance with EN 13183-1 (2002) and EN 408 (2003). Four point bending tests based on EN 408 (2003) with specimen size 50x50x1000 mm was carried out using a Universal testing machine (UTM) to determine the bending strength and Modulus of Elasticity of each timber specie. Characteristic values of Bending strength, Modulus of Rupture and Density were determined using EN 384(2004). Rhizophora racemosa and Syzgium guineense had equilibrium moisture content (EMC) of 10.59 % and 22.34 % respectively. This moisture content were adjusted to 12% using adjustment factors so as to satisfy EN338 (2009) requirements for strength grading of timber. Rhizophora racemosa and Syzgium guineense were assigned to strength class C14 and D24 respectively. The Kolmogorov Smirnov test of goodness of fit test at 95% level of significance (α = 0.05) for bending strength of the two timber species as obtained using Easyfit 5.6 software shows that the most fitted distribution model for bending strength of Rhizophora racemosa is the normal distribution, while Lognormal Distribution is the most fitted for Syzgium guineense.
Computational Engineering and Physical Modeling
Pouyan Press
2588-6959
2
v.
4
no.
2019
24
37
https://www.jcepm.com/article_103543_ad647faeaeba6a8ea904712b0907af1f.pdf
dx.doi.org/10.22115/cepm.2020.159153.1051
Lattice Boltzmann Simulation of Fluid Flow and Heat Transfer through Partially Filled Porous Media
Sheikh
Hassan
Department of Mathematics and Physics, North South University, Dhaka-1229, Bangladesh
author
Taasnim
Himika
Department of Mathematics and Physics, North South University, Dhaka-1229, Bangladesh
author
Md Mamun
Molla
Department of Mathematics and Physics, North South University, Dhaka-1229, Bangladesh
author
Farhad
Hasan
Department of Engineering & Physical Sciences, La Trobe University, Melbourne, VIC 3086, Australia
author
text
article
2019
eng
The main aim of this work is to observe the fluid flow and heat transfer characteristics through porous media at the REV (Representative Elementary Volume) scale in an enclosed squared cavity using LBM (Lattice Boltzmann Method) instead of traditional FVM, FDM, or FEM. Results are generated by varying the porosity (e = 0.4, 0.6, 0.9), and other dimensionless variables: Rayleigh number (Ra = 103, 104, 105, 106), and Darcy number (Da =10-2, 10-3). The enclosed cavity was considered to be half-filled with pore materials, with horizontal porous layer and vertical porous layer, these two cases are studied for all the considered parameters. The influence of the dimensionless parameters as well as porosity on the fluid flow and heat transfer characteristics has been discussed in detail along with the influence of the placement of the pore material inside the cavity. In the end, it is observed form the results that the nature of the flow and rate of the heat transfer are affected significantly by the Ra values, Da values, and porosity level. The placement differences of the pore materials further shows differences in the fluid flow and heat transfer characteristics. A new and simpler forcing term for the porous media is used. This study can be useful while using a porous media in numerical designs and experimental designs. Fortran 90 is used for numerical simulations.
Computational Engineering and Physical Modeling
Pouyan Press
2588-6959
2
v.
4
no.
2019
38
57
https://www.jcepm.com/article_103545_34bb2e8f4402acafd0f1e86c2e2e6b51.pdf
dx.doi.org/10.22115/cepm.2020.200817.1070
Numerical Investigation into the Effect of Laminated Casing on the Impact Resistance of Smartphone Screens
Theddeus
Akano
Department of Systems Engineering, University of Lagos, Akoka, 101017, Lagos, Nigeria
author
Patrick
Olayiwola
Department of Mechanical and Biomedical Engineering, Bells University of Technology, Ota, Ogun State, Nigeria
author
text
article
2019
eng
A survey shows that most smartphones damages are due to frequent falls, owing to their small nature coupled with poor handling. This results in cracked screens to broken parts, to total damage. Although advancements like the gorilla glass which claims to be both scratch and crack resistant have been successful. However, this has only reduced screen damage. The overall effect of high and low-velocity impact on phones has not been reduced. Hence, this study focuses on the impact performance of laminated cellphone casing. The laminate is achieved through force fit of different layers of the lamina. Four laminated scenarios are examined. The impact analyses of single, double, triple, and quadplex layers of the laminate are studied within a drop height of 0.5m - 2.5m and a step size of 0.5m. Various polycarbonate layers of the phone casing are captured as an elastoplastic material model. The assembled model of the phone casing with the screen is achieved through Autodesk Inventor® while Solidworks® drop test module is employed to simulate the different impact conditions. Results from the stress, strain energy, and displacement responses reveal that the number of laminate layers relates inversely to the effect of impact load on the phone screen. The computational outcomes of the present study demonstrate a reasonable agreement with laboratory evidence recorded in the literature.
Computational Engineering and Physical Modeling
Pouyan Press
2588-6959
2
v.
4
no.
2019
58
77
https://www.jcepm.com/article_103544_cae472cf737b96f4bf7638f87817036f.pdf
dx.doi.org/10.22115/cepm.2020.184606.1063
Blast Mitigations of Mid Rise Structures by Cladding Material
K.K.
Kiran
Research Scholar, Civil Engineering Department, Government Engineering College Haveri Karnataka, India
author
Jagadish
Kori
Professor and HOD Civil Engineering Department, Government Engineering College Haveri Karnataka, India
author
text
article
2019
eng
Structure exposed to blast load is unpredictable, causes severe damage to the structure and also takes the life of people.Cladding material is a light weight material, mobile, versatile, economical material used for energy abortion of the structure exposed to blast load. Here a study is made on ten story structure exposed to blast load. Each floor as a three degree of freedom that is one along translation between floor and the structure and two translation between structure and cladding material, totally thirty degree of freedom is considered. The cladding material is used for the connection of every floor. Rubber material is also used for the connection between the cladding and structure. The responses in terms of pressure impulse curve, story drift , story drift ratio is also considered.The maximum energy is observed by using cladding material of the structure and considerable amount of responses is reduced.
Computational Engineering and Physical Modeling
Pouyan Press
2588-6959
2
v.
4
no.
2019
78
94
https://www.jcepm.com/article_104441_c01076a4fc269d7b75c82ef7dca0443c.pdf
dx.doi.org/10.22115/cepm.2020.196935.1066