Main WebsiteAny Enquiry?Contact Us
Main Website

Dr. Amos M Muiruri

Dr. Amos M Muiruri

Lecturer -School of Engineering and Technology
amuiruri@mut.ac.ke

Google Scholar: https://scholar.google.com/citations?user=2pVxV-MAAAAJ&hl=en

Research Gate : https://www.researchgate.net/profile/Amos-Muiruri

LinkedIn :https://www.linkedin.com/in/dr-a-m-muiruri-a3577748/

ORCID: 0000-0002-8455-3731

Download CV

Biography

Dr. (Eng.). Amos Muiruri is a professional mechanical engineering registered with the Engineers Board of Kenya (EBK) and a corporate member of the Institution of Engineer of Kenya (IEK). He hold a BEng (Mechanical Engineering – first class honours) from the Technical University of Kenya, and a MEng (Mechanical Engineering – cum laude) and a PhD (Mechanical engineering) from the Central University of Technology, Free State. He worked as a Mechanical Engineer at CESP, Africa upon completion of his first degree.

He developed for his doctorate, a novel microstructure-variable based constitutive numerical model that quantitively predicts the yield and flow stress of the alloy over a wide range of the field variables of strain rate and temperature. The model was refined and validated using experimental data and implemented as VUHARD and VUMAT material subroutines in ABAQUS/Explicit to generate numerical solutions and used successively to simulate the split Hopkinson pressure bar experiment.

Dr. (Eng.) Muiruri has conducted extensive research on the additive manufacturing of metals, with a specific emphasis on applying this technology within the energy, aviation, and biomedical sectors. He is currently engaged in research focusing on vehicle electrification, which has been acknowledged as a crucial element in achieving global climate change objectives and a significant aspect of sustainable transportation. Furthermore, he is a member of the pioneering team in Kenya trained as trainers for Power to X (PtX), a technology that converts renewable electricity into various energy carriers, such as hydrogen, synthetic fuels, or chemicals, under the GIZ umbrella.

Education

  • PhD in Mechanical Engineering - Central University of Technology, Free state South Africa (CUT)- April 2019 to October 2021
  • MEng. in Mechanical Engineering - Central University of Technology, Free state South Africa (CUT) - cum laude- June 2017 to April 2019
  • Bachelor of Engineering in Mechanical Engineering -The Technical University of Kenya, (TUK)- First Class Honors - January 2011 – May 2015

Publications

  1. M. Muiruri, M. Maringa, W. B. du. Preez, L. M. Masu, “Dynamic behaviour of direct metal laser sintered Ti-6Al-4V (ELI) under high strain rates in compression loading”, Rapdasa International Conference Proceedings Durban, South Africa, pp.165-180: ISBN: 978-0-620-77329-4.
  2. M. Muiruri, M Maringa, W B du Preez & LM Masu, “Effect of Stress Relieving Heat Treatment on High Strain Rate Tensile Properties of Direct Melting Laser Sintered (DMLS) Parts”, 7th International Conference on Competitive Manufacturing (COMA-19), January 30 – February 1, 2019, Wallenberg Centre (STIAS), Stellenbosch, South Africa. ISBN No: 978-0-7972-1779-9.
  3. M. Muiruri, M Maringa & W B du Preez, “Constitutive Numerical Modelling in Additive Manufacturing: Challenges in Predicting the Yield Strength and Flow Properties of Alloys”, Rapdasa International Conference Proceedings, 06 – 08 November 2019, Emoya Estate, Bloemfontein, South Africa, pp. 190-203. ISBN 978-0-6398390-0-4.
  4. A.M. Muiruri, M. Maringa & W.B.du, Preez, “Application of Phenomenological Modelling in the Development of a Database for Additively Manufactured Ti6Al4V (ELI): A Review” 10th International Conference of the African Materials Research Society (AMRS2019), 10 – 13 December 2019 Arusha, Tanzania
  5. Amos Muiruri; Maina Maringa; Willie du Preez. ‘Theoritical model of the flow properties of post processed direct metal laser sintering Ti6Al4V’ 6th World Congress on Integrated Computational Materials Engineering (ICME 2022): On-Demand Oral Presentations, Hyatt Regebcy Lake Tahoe, Nevada, USA, April 24- 25, 2022 http://www.programmaster.org/PM/PM.nsf/ViewSessionSheets?OpenAgent&ParentUNID=75AB275E 59AC7CE9852587C100531136
  6. Muiruri M., Maringa M. and du Preez. W.B. Influence of Macro-Residual Stresses on the Impact and Compressive Behaviour, as well as Failure Characteristics of Parts Produced by Laser Powder Bed Fusion, Proceedings of the Sustainable Research and Innovation Conference, 2023, Jomo Kenyatta University of Agriculture and Technology, Juja Kenya, 4th – 5th October 2023.
  7. I. Chibinyani, T.C. Dzogbewu, M. Maringa, A.M. Muiruri. A Review of the Types, Occurrence, and Applications of Cellular Structures in Nature, Proceedings of the Sustainable Research and Innovation Conference, 2023, Jomo Kenyatta University of Agriculture and Technology, Juja Kenya, 4th – 5th October 2023.
  8. Tumelo D. Moloi, Thywill C. Dzogbewu, Maina Maringa, Amos M. Muiruri. Quasi-Static Tensile Properties of LPBF Ti6Al4V (ELI) Parts Exposed to Two Different Heat Treatment Processes and Tested at Different Elevated Temperatures, Proceedings of the Sustainable Research and Innovation Conference, 2023, Jomo Kenyatta University of Agriculture and Technology, Juja Kenya, 4th – 5th October
  9. Munashe Chibinyani, Thywill Dzogbewu, Maina Maringa, Amos Muiruri. A review of the types and tessellation of lattice structures, their effectiveness and limitations in mimicking natural cellular 2023 RAPDASA-RobMech-PRASA-AMI Conference. MATEC Web Conf. , vol. 388, 06008, 2023. https://doi.org/10.1051/matecconf/202338806008

Journal papers

  1. A M Muiruri, M Maringa, W B du Preez, L M Masu, “ Variation of impact toughness of as-built DMLS Ti6Al4V (ELI) specimens with temperature”, South African Journal of Industrial Engineering, November 2018 Vol 29(3) special edition, pp 284-298. ISSN 224-7890.
  2. A M Muiruri, M Maringa, W B du Preez & LM Masu, “Effects of Stress-Relieving Heat Treatment on Impact Toughness of Direct Metal Laser Sintering (DMLS)-Produced Ti6Al4V (ELI) Parts”, JOM (2019) doi:10.1007/s11837-019-03862-5
  3. Amos Muiruri, Maina Maringa, Wille du Preez and Leonard Masu, “Effect of stress-relieving heat treatment on the high strain rate dynamic compressive properties of Additively Manufactured Ti6Al4V(ELI)”, Metal, 2020, 10(5), doi:org/10.3390/met10050653.
  4. Amos Muiruri, Maina Maringa, Willie du Preez, “Crystallographic texture analysis of as- built and heat-treated Ti6Al4V (ELI) produced by Direct Metal Laser Sintering”, Crystals 2020, 10, 699; doi:10.3390/cryst10080699
  5. Amos Muiruri, Maina Maringa, Willie du Preez, “Evaluation of dislocation densities in various microstructures of additively manufactured Ti6Al4V(ELI) by the method of X-ray diffraction”, Materials 2020, 13, 5355; doi:10.3390/ma13235355
  6. Muiruri, A., Maringa, M., du Preez, W. High strain rate properties of various forms of Ti6Al4V(ELI) produced by direct metal laser sintering. Applied Sciences 2021, 11(17), 8005; org/10.3390/app11178005
  7. Muiruri, A.; Maringa, M.; Preez, W.d. Validation of a Microstructure-Based Model for Predicting the High Strain Rate Flow Properties of Various Forms of Additively Manufactured Ti6Al4V(ELI)Alloy. Metals 2021, 11, 1628. https://doi.org/10.3390/met11101628
  8. Muiruri, ; Maringa, M.; du Preez, W. Development of VUMAT and VUHARD Subroutines for Simulating the Dynamic Mechanical Properties of Additively Manufactured Parts. Materials 2022, 15, 372. https://doi.org/10.3390/ma15010372
  9. Muiruri, A.; Maringa, M.; Preez, W.d. Numerical Simulation of High Strain Rate and Temperature Properties of Laser Powder Bed Fusion Ti6Al4V(ELI) Determined Using a Split Hopkinson Pressure Bar. Materials 2022, 15, 1872. https://doi.org/10.3390/ma1505187
  10. Muiruri, ; Maringa, M.; du Preez, W. Statistical Analysis of the Distribution of the Schmid Factor in As-Built and Annealed Parts Produced by Laser Powder BedFusion. Crystals 2022, 12, 743. https://doi.org/10.3390/cryst12050743
  11. Muiruri, A.; Maringa, M.; du Preez, W. Quasi-Static Mechanical Properties of Post-Processed Laser Powder Bed Fusion Ti6Al4V(ELI) Parts under Compressive Loading. Sci. 2022, 12, 9552. https://doi.org/10.3390/app12199552
  12. M. Muiruri, M. Maringa, W. du Preez, “A Theoretical Model of the Flow Properties of Postprocessed Direct Metal Laser Sintering Ti6Al4V (ELI)”, Advances in Materials Science and Engineering, vol. 2022, Article ID 4048913, 12 pages, 2022. https://doi.org/10.1155/2022/4048913
  13. I. ChibinyaniI,*; T.C. DzogbewuI; M. MaringaI; A.M. MuiruriII, Reduced order topology optimisation of a planar honeycomb defined by a linear elastic Ti6Al4V (ELI) material model, SAJIE, vol.33, no.3.2022 http://dx.doi.org/10.7166/33-3-2808
  14. Muiruri, A.; Maringa, M.; du Preez, W. Numerical Simulation of the Taylor Impact Test for Laser Powder Bed Fusion Parts Based on Microstructural Internal State Variables. Sci. 2023, 13, 5372. https://doi.org/10.3390/app13095372
  15. I. Chibinyani, T.C Dzogbewu, M. Maringa, A.M. Muiruri. Numerical modelling of DMLS Ti6Al4V(ELI) polygon structures, Results in Materials, vol.20, 100456, 2023. https://doi.org/10.1016/j.rinma.2023.100456
  16. M.I. Chibinyani, T.C Dzogbewu, M. Maringa, A.M. Muiruri. Numerical modelling of Ti6Al4V(ELI) hierarchical honeycomb structures of order obe at the vertices. Results in Engineering, vol. 21, 102024 (2024). https://doi.org/10.1016/j.rineng.2024.102024
  17. Tumelo Moloi, Thywill Cephas Dzogbewu, Maina Maringa, Amos Muiruri. Quasi-static tensile properties of DMLS TI6AL4V (ELI) specimens exposed to two different heat treatment processes and tested at different elevated temperatures. Results in Engineering, vol.22, 102290, 2024. https://doi.org/10.1016/j.rineng.2024.102290
  18. Muiruri, A.; Maringa, ; du Preez, W. Effects of Quasi-Static Strain Rate and Temperature on the Microstructural Features of Post-Processed Microstructures of Laser Powder Bed Fusion Ti6Al4V Alloy. Appl. Sci. 2024, 14, 4261. https://doi.org/10.3390/app14104261
  19. Chibinyani, M.I.; Dzogbewu, T.C.; Maringa, M.; Muiruri, A. Lattice Structures Built with Different Polygon Hollow Shapes: A Review on Their Analytical Modelling and Engineering Appl.Sci. 2024, 14, 1582. https://doi.org/10.3390/app14041582
  20. Amos Muiruri, Maina Maringa, Willie du Preez, X-ray diffraction profile analysis of martensitic Ti6Al4V (ELI) parts produced by laser powder bed fusion. MATEC Web of Conferences 388, 10003(2023), https://doi.org/10.1051/matecconf/202338810003
  21. Munashe Chibinyani, Thywill Cephas Dzogbewu, Maina Maringa, Amos Muiruri, A review of the types and tessellation of lattice structures, their effectiveness and limitations in mimicking natural cellular structures. MATEC Web of Conferences 388, 06008(2023), https://doi.org/10.1051/matecconf/202338806008