PhD Researcher · Cambridge

Lowhikan
Sivananthasarma

Department of Engineering, University of Cambridge, United KingdomDepartment of Engineering,
University of Cambridge,
United Kingdom

I study the structural stability of thin-walled cold-formed steel members, with a focus on buckling behaviour, geometric imperfections, and optimisation under uncertainty. My broader research interests span structural optimisation, steel structures, computational form-finding, additive manufacturing, and optics-based measurement techniques.

01

Research

01 / PhD RESEARCH

Modal Decomposition of Structural Instabilities and Geometric Imperfections

Developing the Polarization Method for decomposing FSM eigenmodes of thin-walled steel members into physically pure local, distortional, global, and shear/extension mode components using energy-orthogonal projections.

Modal DecompositionPolarization MethodThin-Walled SteelImperfections
02 / MSc RESEARCH

Structural Optimization and Generative Design

Developed a parametric generative design workflow integrating structural optimization and finite element analysis to produce manufacturable CAD models of civil engineering structures.

Structural OptimizationGenerative DesignSkeletonizationDesign-Informed Optimization
03 / BSc RESEARCH

Computer Vision for Structural Health Monitoring

Developed a Digital Image Correlation algorithm and GUI to compute displacement and strain fields from mobile camera images, validated experimentally against laboratory measurements.

Computer VisionDigital Image CorrelationExperimental Mechanics
View project
02

Publications

Modal Decomposition of Structural Instabilities and Geometric Imperfections
2026
CIMS 2026 · 9th International Conference on Coupled Instabilities in Metal Structures
Modal Decomposition of Geometric Imperfections Using the Polarization Method
L. Sivananthasarma & J. Becque
2026
EUROSTEEL 2026 · 11th European Conference on Steel and Composite Structures
L. Sivananthasarma & J. Becque
Structural Optimization and Generative Design
2026
Thin-Walled Structures · Elsevier
C. Fernando, S. Herath & L. Sivanantha Sarma
Journal Paper
2024
Computers and Structures · Elsevier · Vol. 302, p. 107474
S. Lowhikan, H.M.S.T. Herath & H.M.Y.C. Mallikarachchi
Journal Paper
2022
Proc. Annual Sessions, Society of Structural Engineers Sri Lanka · Colombo
S. Lowhikan & H.M.S.T. Herath
Conference
2022
MERCon 2022 · 8th Int. Moratuwa Engineering Research Conference · Colombo
S.K.L. Gunawardhana, S. Lowhikan & H.M.S.T. Herath
Conference
Computer Vision for Structural Health Monitoring
2022
MERCon 2022 · 8th Int. Moratuwa Engineering Research Conference · Colombo
S. Lowhikan & H.M.Y.C. Mallikarachchi
Conference
2020
Proc. Annual Sessions, Society of Structural Engineers Sri Lanka · Colombo
N. Sujeeka, S. Lowhikan & H.M.Y.C. Mallikarachchi · Zenodo
Conference
03

Teaching

Delivering undergraduate teaching and supervision in structural analysis, mechanics, and computational mechanics across leading universities in the UK and Sri Lanka.

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04

Work

Applying structural engineering expertise through consulting and industry roles in structural assessment, design, and construction site engineering.

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05

Software

MATLAB · Open Source
FSM-Lab
A MATLAB application for buckling analysis and modal decomposition of thin-walled cold-formed steel members. FSM-Lab implements the Finite Strip Method with full modal decomposition capabilities using the Polarization Method and Nodal Force Method, supporting various cross-section geometries, signature curve generation, and visualisation of mode shapes.
GitHub Request Access
RELEASING SOON
FSM-Lab v1.0
K₁K₂
Energy Decomposition
Bending and membrane energy separated across all mode classes
L·D·G·T·S
Modal Subspaces
Local, distortional, global, transverse extension, and shear mode decomposition
σ(λ)
Signature Curves
Critical buckling load vs. half-wavelength curves for stability analyses
2D·3D
Visualisation
2D and 3D buckling mode shape visualisation for any cross-section and half-wavelength
06

About

I am a PhD candidate in the Structures Division of the Department of Engineering at the University of Cambridge, supervised by Dr Jurgen Becque and funded by the Cambridge Trust and Trinity College. My research focuses on thin-walled steel structures, developing modal decomposition methods to characterize buckling modes and geometric imperfections.

I hold a BSc in Engineering (First Class Honours) and an MSc in Structural Engineering from the University of Moratuwa, Sri Lanka. Prior to my PhD, I served as a Visiting Lecturer at the University of Moratuwa (Department of Architecture) and at the University of Vocational Technology, Sri Lanka.

My research interests include structural optimization, thin-walled steel structures, computational mechanics, machine learning applications, optical-based techniques, and computational form-finding.

Education
PhD Engineering2023 – Present
University of Cambridge, UK
Advisor: Dr Jurgen Becque
MSc Civil Engineering2021–23
University of Moratuwa, Sri Lanka
Advisors: Prof. Mallikarachchi & Dr Herath
BSc Civil Engineering (First Class Hons)2016–21
University of Moratuwa, Sri Lanka
Get in touch

Let's talk about
structures.

Open to research collaborations or any questions — feel free to reach out.