A5022768756- Acoustic Wave Phenomena Research
- Structural Analysis and Optimization
- Planetary Science and Exploration
- Spacecraft Design and Technology
- Cellular and Composite Structures
- Structural Health Monitoring Techniques
- Advanced Materials and Mechanics
- Ultrasonics and Acoustic Wave Propagation
- Space Satellite Systems and Control
- Optical measurement and interference techniques
- Dynamics and Control of Mechanical Systems
- Vibration and Dynamic Analysis
- Aerodynamics and Acoustics in Jet Flows
- Noise Effects and Management
- Speech and Audio Processing
- Astro and Planetary Science
- Textile materials and evaluations
- Elasticity and Material Modeling
- Mechanical Engineering Research and Applications
- Composite Structure Analysis and Optimization
- Aeroelasticity and Vibration Control
- Distributed and Parallel Computing Systems
- Hydraulic Fracturing and Reservoir Analysis
- Solidification and crystal growth phenomena
- Space exploration and regulation
KTH Royal Institute of Technology
2015-2024
Wallenberg Wood Science Center
2024
This paper investigates the vibration characteristics of multi-span beams resting on an elastic foundation and subjected to axial forces. A comprehensive analytical expression dynamic response that is developed address various boundary conditions. The equation derived by employing Newton's second law. By Laplace transformations Green's function method, solution this governing can be obtained. Subsequently, a unified description implemented for distinct types conditions using matrix...
In the near future, autonomous space systems will compose a large number of spacecraft being deployed. Their tasks involve rendezvous and proximity operations with structures, such as inspections or assembly orbiting stations maintenance human-assistance over shared workspaces. To promote replicable reliable scientific results for control spacecraft, we present design laboratory based on open-source modular software hardware. The simulation provides software-in-the-loop (SITL) architecture...
Metamaterials, man-made composites that are scaled smaller than the wavelength, have demonstrated a huge potential for application in acoustics, allowing production of sub-wavelength acoustic absorbers, invisibility, perfect mirrors and lenses hyper focusing, illusions enabling new degrees freedom control field. The zero, or even negative, refractive sound index metamaterials offers possibilities patterns at scales. Despite tremendous growth research on during last decade, metamaterial-based...
The rapidly growing use of small satellites for space missions requires deployable systems to be highly storable yet large and with adequate mechanical properties when deployed. This paper focuses on the modeling simulation a meter-class passively boom, based self-contained linear exploiting bistable nature composite shells. Experimental tests were performed boom prototype suspended in gravity offloading system. strain energy level, deployment time, spacecraft displacements calculated from...
Bistable tape springs are suitable as deployable structures thanks to their high packaging ratio, self-deployment ability, low cost, light weight, and stiffness. A booms assembly composed of four 1-m long bistable glass fiber was designed for the electromagnetically clean 3U CubeSat Small Explorer Advanced Missions (SEAM). The aim present study investigate deployment dynamics reliability SEAM boom design after long-term stowage using onground experiments simulations. gravity offloading...
Bistable tape springs are ultrathin fiber-reinforced polymer composites, which could self-deploy through releasing stored strain energy. Strain energy relaxation is observed after long-term stowage of bistable due to viscoelastic effects and the might lose their self-deployment abilities. In order mitigate thus ensure self-deployment, different were designed, manufactured, tested. Deployment experiments show that a four-layer, [−45/0/90/45], plain weave glass fiber spring has high capability...
Simple geometric distortions applied to the isometric Kelvin cell structures, (the tetrakaidecahedron), are shown result in equivalent materials with anisotropic Hooke's tensors. The material models estimated using a recently published inversion method where 21 independent elastic constants of tensor identified. In these geometries, some faces have been twisted and/or tilted. Numerical experiments suggest that distorted cells exhibit variations compression, shearing, shear-compression and...
This paper proposes an inverse estimation method for the extraction of equivalent, static elastic, Hooke's tensor. The inversion is based on a fitting displacements, obtained from combination compression and shear traction loads, faces sample specimen. An homogenised material model found by varying elastic moduli until defined cost function, error measured as difference between displacement fields, has reached minimum, at which anisotropic constitutive solid been identified. built...
Metamaterials, man-made composites scaled smaller than the wavelength, have demonstrated a huge potential in their applications acoustics, opening up for sub--wavelength acoustic absorbers, invisibility, perfect mirrors and lenses hyper focusing, illusions enabling new degrees of freedom control field. The zero, or even negative, refractive sound index metamaterials offers possibilities pattern at scales. Despite tremendous growth research on during last decade, metamaterial-based...
This paper proposes an experimental method for observing the anelastic anisotropic behaviour of poroelastic media. The setup relies on three-dimensional digital image correlation, enabling acquisition full-field displacement data from visible faces a vibrating cubic material sample. latter is placed in vacuum chamber, loaded with seismic mass and excited uniaxially. observability relevance field assessed by means numerical simulation. A homogenised fully model used, implemented using finite...
The scaling law for ferroelectric stripe domains is investigated in free-standing BaTiO3 and PbTiO3 thin films via phase-field simulations. results agree with the Kittel law, where square of domain width found to be proportional film thickness. After being rescaled by corresponding wall thickness, generalized also demonstrated, dimensionless constant M estimated ∼3.3 two materials. Moreover, we predict effect exchange which incorporated Ginzburg-Landau theory on equilibrium critical thickness films.
Previously reported measurements of uniaxial compression cellular acoustic materials have shown an intriguing loss stiffness in the regions close to boundaries. The present contribution attempts further investigate if these effects may be modelled by assuming a local alteration microstructure boundaries resulting from cutting block material into smaller samples. Assuming that fewer struts contribute locally mechanical behaviour, implies reduced equivalent porosity, or relative density,...
A deployable space web is a flexible structure that can act as lightweight platform for construction of large structures in space. In order to save and energy small ...
The dynamic behaviour of a novel anisotropic cellular micro-structural geometry derived from the basic symmetric Kelvin cell is discussed for varying relative density. cells are arranged in cubic array and response studied classical seismic mass setup using beam elements to represent ligaments cell. eigenfrequencies eigenmodes computed together with forced simulations where proportional damping model Young's modulus assumed. frequency dependence based on fractional derivative representation....