Marine and Arctic Technology
Marine technology investigates the responses and strength of ships in a complex physical environment where ice- and wave-induced loads are present. We also investigate the system-level issues at the scales of shipping systems and fleets as well as individual ships and their subsystems. The focus is on passenger and ice-going ships and on autonomous ships.
The core ideas of the research are to ensure safety, to enable sustainability through advanced solutions and to focus on the first principles of applied mechanics (e.g. hydrodynamics and structures), statistical methods and systems engineering.
Arctic marine technology studies the behaviour of ships and structures in ice. Arctic marine research focuses on ice loads on ships and structures, on ship performance and on ship safety. The group studies these topics by conducting extensive full-scale trials onboard ice-going ships, by utilising the Aalto Ice Tank and by developing theoretical models for e.g. ice load stochasticity and ultimate strength of structures.
The group has excellent international and national networks, including the Joint Research Center of Excellence for Arctic Shipping and Operations (CEARCTIC) funded by Lloyd's Register Foundation in London and led by Aalto University.
Ice mechanics research focuses on gaining detailed and fundamental knowledge on the physical phenomena behind the behaviour of sea ice and ice loads. Only by building our understanding of sea ice behaviour can we improve predictions on ice-induced loads on ships and structures.
We have a strong background in numerical ice mechanics and use simulations of complex ice loading scenarios in our work. Related to this, we develop tools for discrete element and combined finite-discrete element method simulations. We also conduct well-controlled model-scale experiments in Aalto Ice Tank, a unique testing facility, as well as field work.
Advanced structures and materials research studies the mechanical behavior of high-performance materials, lattice materials, material systems and structures. We also develop high-performing structures in order to meet requirements of society by considering the quality produced at laboratory and industrial scale. We are focusing our research on load response and failure mechanisms of materials and structures under different types of loadings, which occur in short- and long-terms. The load types are static, fatigue, extreme (ultimate) and impact loading. We do extensive experimental research to deepen our understanding of materials and structures and to gain data for material and structure modelling, which is the other branch of our research work.
In our research, we use the latest numerical techniques, based on the finite element method (FEM), and homogenisation to get insight into theoretical modelling and prevailing assumptions. We also aim for simple theoretical models to speed up the design processes for complex structural systems. Our research groups have their own fields of interest in terms of materials and structures. Synergies between the groups lie especially in experimental and modelling methods. Most of our activities are focused on high-strength steel structures, composite structures made of fiber-reinforced and hybrid laminates, lattice materials and wooden structures. In these areas, the focus is on how the materials' microstructures affect strength and stiffness. Interfaces such as welded joints and adhesively bonded joints are essential elements of advanced structures and also in the core of our research.
Structural topology plays key role in high-performing structures and materials. Lattice materials, such as honeycombs, are among the lightest, stiffest and strongest materials available today. These porous materials can be fabricated out of nearly any parent material (polymers, metals or ceramics) with cell sizes ranging from nanometers to millimetres. Lattices have a huge advantage over conventional materials: by choosing the solid they are made from and their topology it is possible to create new materials with specific, and often unique, combinations of properties. As a new field, our group is working to create novel lattice architectures by taking advantage of the rapid developments in 3D printing technology. This work combines analytical, numerical and experimental methods to provide a better understanding of the mechanical behaviour of lattice materials.
Arctic marine operations are increasing with growth in sea transportation as well as off-shore wind energy and drilling operations. The Arctic is a harsh but sensitive environment that sets stringent requirements for safety and efficiency. Our group combines expertise in mechanical and safety engineering, naval architecture, applied and solid mechanics and risk management to ensure that future operations are able to meet these requirements.
Our multidisciplinary Arctic marine technology research creates knowledge on the interactions of sea ice with vessels for ship design and operational contexts. This knowledge is applied in practical applications while also supporting marine policy. The development of safety requirements has to rely on concepts, methods and frameworks for safe technological and socio-technological systems for design and operations, and for managing associated risks. This serves society by increasing our understanding of how maritime safety is created and maintained, and how maritime risks can be effectively managed.
One active research area is ship-ice interaction, which is of crucial importance for understanding both the resistance of ships in ice and the ice-induced loads on ships navigating sea ice environments. We conduct extensive experiments and measurements in full and model scale, including simultaneous ice thickness and ice load measurements onboard vessels and experimental programs in Aalto Ice Tank. We aim to improve our understanding of the critical elements for the safe design and operation of ships, including the effect of stochastic ice-induced loads on ship performance in dynamic and complex ice fields.
We also have a strong focus on numerical ice mechanics. As ice loads are caused by a complex ice-structure interaction process in which ice breaks into discrete ice blocks, novel research methods are needed. We use and develop tools for discrete element and combined finite-discrete element method (DEM and FEM-DEM) simulations. DEM and FEM-DEM allow us to model long ice loading processes, while accounting for ice failure and individual ice blocks.
Our simulation-based analysis has provided new insight on ice mechanics. We have, for example, showed that the so-called force chains have an important role on the ice loads and have been able to quantify their effect. We have also studied the effect of ice properties on ice loads. In addition, we have used DEM and FEM-DEM to study the statistics of ice loads and the behavior of ice rubble.
A central part of our research is Aalto Ice Tank, a unique 40 x 40-meter ice basin. Typical ice tank experiments include resistance, propulsion and manoeuvring tests on ships in ice, tests on ice loads on marine structures, and modelling of natural ice formations, such as ice ridges and ice rubble. Aalto Ice Tank also enables a wide range of other experiments on the physical phenomena related to sea ice, such as experiments on ice fracture, and offers a platform for rigorous validation of numerical models.
The group chairs the Centre of Excellence for Arctic Shipping and Operations funded by the Lloyds Register Foundation and is a member of SAMCoT, the Center for Research-based Innovation on Sustainable Arctic Marine and Coastal Technology led by the Norwegian University of Science and Technology and funded by the Norwegian Research Council and international industry. The group has also other close international partners in USA, China and Japan.
Risk and safety research is focused on developing concepts, methods, tests and frameworks for creating safe technological and socio-technological systems and for managing associated risks. These advances in risk analysis and safety science are applied to specific problems in maritime and materials engineering. This serves society by increasing our understanding of how maritime and materials safety is created and maintained and how safety risks can be managed effectively.
Given the rapid developments in marine technologies, with increased automation, digitalisation, and system integration, there is a constant need for ensuring the safety of design and operation of new maritime systems. Scenario-based risk modelling is essential for the safe operation of ships and maritime traﬃc systems. Advanced ships require new and improved designs and smart situation awareness and decision support systems. In order to achieve this, the research of the Marine Technology research group focuses on the development of innovative ship designs accounting with efficient traffic management systems and navigation safety controls.
In the context of Arctic navigation, the current design regulations for ice-going ships and oﬀshore structures fail to predict the actual safety and required safety level of the operations. Holistic risk analyses typically include the deﬁnition of hazard scenarios, their probability of occurrence and the severity of their consequences. Such an assessment is challenging for Arctic operations, as operational data is scarce. In this area, one of the goals is to apply similar methods to those developed for the safety of marine traﬃc in open waters – particularly the heavy tanker traﬃc in the Gulf of Finland – to ice-covered waters. In addition, model-scale testing in Aalto Ice Tank represents an important part of this research as it provides new insight into the structure-ice contact problem.