Search results

Filters

  • Journals
  • Authors
  • Keywords
  • Date
  • Type

Search results

Number of results: 2
items per page: 25 50 75
Sort by:
Download PDF Download RIS Download Bibtex

Abstract

The measurement of frequency characteristics, like magnitude and phase, related to a specific transfer function of DC–DC converters, can be a difficult task – especially when the measured signal approaches the boundary of a small-signal model validity (i:e. 1/3 of the switching frequency fS). It is hard to find a paper where authors mention the measurement techniques they use to draw frequency characteristics. Meanwhile the presence of noise in the output signal does not enable to directly measure the gain and the phase shift between the input and output signals. In such situations additional analysis is required in order to achieve a reliable result. This paper contains a description of a few methods that can be used to analyse measured signals in order to determine the gain and the phase shift of a specific transfer function. They enable to verify mathematical models in a wide range of frequencies (up to 1/3 fS). The methods use signals measured in the time domain and can be implemented in mathematical software such as Matlab or Scilab.

Go to article

Authors and Affiliations

Marcin Walczak
Download PDF Download RIS Download Bibtex

Abstract

The flexural toughness of chopped steel wool fiber reinforced cementitious composite panels was investigated. Reinforced cementitious composite panels were produced by mixing of chopped steel wool fiber with a ratio range between 0.5% to 6.0% and 0.5% as a step increment of the total mixture weight, where the cement to sand ratio was 1:1.5 with water to cement ratio of 0.45. The generated reinforced cementitious panels were tested at 28 days in terms of load-carrying capacity, deflection capacities, post-yielding effects, and flexural toughness. The inclusion of chopped steel wool fiber until 4.5% resulted in gradually increasing load-carrying capacity and deflection capacities while, provides various ductility, which would simultaneously the varying of deflection capability in the post-yielding stage. Meanwhile, additional fiber beyond 4.5% resulted in decreased maximum load-carrying capacity and increase stiffness at the expense of ductility. Lastly, the inclusion of curves gradually.
Go to article

Bibliography


[1] Rajak D.K., Pagar D. D., Menezes P. L., and Linul E, “ Fiber-reinforced polymer composites: Manufacturing, properties, and applications”, Polymers 11: p. 1667, 2019. https://doi.org/10.3390/polym11101667
[2] Rajak D.K., Pagar D.D., Kumar R., and Pruncu C.I., “Recent progress of reinforcement materials: A comprehensive overview of composite materials”, Journal of Materials Research and Technology, 8: pp. 6354–6374, 2019. https://doi.org/10.1016/j.jmrt.2019.09.068
[3] Cejuela E., Negro V., and del Campo J.M., “Evaluation and Optimization of the Life Cycle in Maritime Works”, Sustainability 12: 4524, 2020. https://doi.org/10.3390/su12114524
[4] Pushkar S. and Ribakov Y., “Life-Cycle Assessment of Strengthening Pre-Stressed Normal-Strength Concrete Beams with Different Steel-Fibered Concrete Layers”, Sustainability 12: p. 7958. 2020. https://doi.org/10.3390/su12197958
[5] Rashiddadash P., Ramezanianpour A.A., and Mahdikhani M., “Experimental investigation on flexural toughness of hybrid fiber reinforced concrete (HFRC) containing metakaolin and pumice”, Construction and Building Materials 51: pp. 313–320, 2014. https://doi.org/10.1016/j.conbuildmat.2013.10.087
[6] Felekoğlu B.,Türkel S.,and Altuntaş Y., “Effects of steel fiber reinforcement on surface wear resistance of self-compacting repair mortars”, Cement and Concrete Composites 29: pp. 391–396, 2007. https://doi.org/10.1016/j.cemconcomp.2006.12.010
[7] Abdulkareem M., Havukainen J., and Horttanainen M., “How environmentally sustainable are fibre reinforced alkali-activated concretes?”, Journal of Cleaner Production 236: p. 117601, 2019. https://doi.org/10.1016/j.jclepro.2019.07.076
[8] Zhang P., Zhao Y-N, Li Q-F, Wang P., and Zhang T.H., “Flexural toughness of steel fiber reinforced high performance concrete containing nano-SiO2 and fly ash”, The Scientific World Journal 1–11 2014. https://doi.org/10.1155/2014/403743
[9] Faris, M.A., Abdullah, M.M.A.B., Ismail, K.N., Mortar, N.A.M., Hashim, M.F.A. and Hadi, A. “Pull-Out Strength of Hooked Steel Fiber Reinforced Geopolymer Concrete”, In IOP Conference Series: Materials Science and Engineering 55: pp. 012–080, 2019. https://doi:10.1088/1757-899X/551/1/012080
[10] Aggelis D.G., Soulioti D., Barkoula N.M., Paipetis A.S., Matikas T.E., and Shiotani T., “Acoustic emission behavior of steel fibre reinforced concrete under bending”, Construction and Building Materials 23: pp. 32–40, 2009. https://doi.org/10.1016/j.conbuildmat.2009.06.042
[11] Ragalwar K., Heard W.F., Williams B.A., Kumar D., and Ranade R., “On enhancing the mechanical behavior of ultra-high performance concrete through multi-scale fiber reinforcement”, Cement and Concrete Composites 105: p. 103422, 2020. https://doi.org/10.1016/j.cemconcomp.2019.103422
[12] Amer, Akrm A. Rmdan, Mohd Mustafa Al Bakri Abdullah, Yun Ming Liew, Ikmal Hakem A Aziz, Jerzy J. Wysłocki, Muhammad Faheem Mohd Tahir, Wojciech Sochacki, Sebastian Garus, Joanna Gondro, and Hetham AR Amer, “Optimizing of the Cementitious Composite Matrix by Addition of Steel Wool Fibers (Chopped) Based on Physical and Mechanical Analysis”, Materials 14: p. 1094, 2021. https://doi.org/10.3390/ma14051094
[13] Sharma, A.K., Bhandari, R., Aherwar, A. and Rimašauskienė, R, “Matrix materials used in composites: A comprehensive study”, Materials Today: Proceedings 21: pp. 1559–1562, 2020. https://doi.org/10.1016/j.matpr.2019.11.086
[14] García A., Norambuena-C. J., and Partl, M.N., “A parametric study on the influence of steel wool fibers in dense asphalt concrete”, Materials and Structures 47: 1559–1571, 2014. https://doi.10.1617/s11527-013-0135-0
[15] Ponikiewski T., Katzer J., Bugdol M., and Rudzki M., “Determination of 3D porosity in steel fibre reinforced SCC beams using X-ray computed tomography”, Construction and Building Materials 68: pp. 333–340, 2014. https://doi.org/10.1016/j.conbuildmat.2014.06.064
[16] Koenig A., “Analysis of air voids in cementitious materials using micro X-ray computed tomography (µXCT)”, Construction and Building Materials 244:118313, 2020. https://doi.org/10.1016/j.conbuildmat.2020.118313
[17] Chajec A., and Sadowski L., “The Effect of Steel and Polypropylene Fibers on the Properties of Horizontally Formed Concrete”, Materials 13: p. 5827, 2020. https://doi.org/10.3390/ma13245827
[18] Zhou S., Xie L., Jia Y., and Wang C., “Review of cementitious composites containing polyethylene fibers as repairing materials”, Polymers 12: p. 2624, 2020. https://doi.org/10.3390/polym12112624
[19] Martinelli E., Pepe M., and Fraternali F., “Meso-Scale Formulation of a Cracked-Hinge Model for Hybrid Fiber-Reinforced Cement Composites”, Fibers 8: p. 56, 2020. https://doi.org/10.3390/fib8090056
[20] Zhou H., Jia B., Huang H., and Mou Y., “Experimental study on basic mechanical properties of basalt fiber reinforced concrete “, Materials (Basel) 13: p. 1362, 2020. https://doi.org/10.3390/ma13061362
Go to article

Authors and Affiliations

Akrm A. Rmdan Amer
1
ORCID: ORCID
Mohd Mustafa Al Bakri Abdullah
2
ORCID: ORCID
Yun Ming Liew
2
ORCID: ORCID
Ikmal Hakem A. Aziz
1
ORCID: ORCID
Muhammad Faheem Mohd Tahir
2
Shayfull Zamree Abd Rahim
3
ORCID: ORCID
Hetham A.R. Amer
4
ORCID: ORCID

  1. Geopolymer & Green Technology, Center of Excellence (CEGeoGTech), Universiti Malaysia Perlis (UniMAP), Perlis, Malaysia
  2. Faculty of Chemical Engineering Technology, Universiti Malaysia Perlis, Malaysia
  3. Faculty of Mechanical Engineering Technology, Universiti Malaysia Perlis (UniMAP), Perlis, Malaysia
  4. Omar Al-Mukhtar Universiti, Civil Engineering Department, Libya

This page uses 'cookies'. Learn more