Jakub Lengiewicz

Jakub Lengiewicz
University of Luxembourg · Faculty of Science, Technology and Medicine (FSTM)

Ph.D.

About

37
Publications
11,376
Reads
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717
Citations
Introduction
Jakub Lengiewicz is currently an MSCA-IF fellow at the University of Luxembourg. He is also affiliated with the Institute of Fundamental Technological Research of the Polish Academy of Sciences. Jakub does research in Computing in Mathematics, Natural Science, Engineering and Robotics. His current project is 'Mechanics of Programmable Matter.'
Additional affiliations
January 2009 - present
Institute of Fundamental Technological Research
Position
  • Professor (Assistant)
Education
October 2003 - June 2008
Institute of Fundamental Technological Research
Field of study
  • Computational Mechanics
October 1996 - May 2002
University of Warsaw
Field of study
  • Informatics

Publications

Publications (37)
Article
Full-text available
We propose a new class of modular-robotic structures, intended to produce forces which scale with the number of modules. We adopt the concept of a spherical catom and extend it by a new connection type which is relatively strong but static. We examine analytically and numerically the mechanical properties of two collective-actuator designs. The sim...
Article
Full-text available
We propose a methodology of planning effective shape shifting and locomotion of large-ensemble modular robots based on a cubic lattice. The modules are divided into two groups: fixed ones, that build a rigid porous frame, and mobile ones, that flow through the frame.Mobile modules which flow out of the structure attach to the frame, advancing its b...
Article
Full-text available
Solid contacts involving soft materials are important in mechanical engineering or biomechanics. Experimentally, such contacts have been shown to shrink significantly under shear, an effect which is usually explained using adhesion models. Here we show that quantitative agreement with recent high-load experiments can be obtained, with no adjustable...
Article
Full-text available
We present a distributed framework for predicting whether a planned reconfiguration step of a modular robot will mechanically overload the structure, causing it to break or lose stability under its own weight. The algorithm is executed by the modular robot itself and based on a distributed iterative solution of mechanical equilibrium equations deri...
Article
Full-text available
For many novel applications, such as patient-specific computer-aided surgery, conventional solution techniques of the underlying nonlinear problems are usually computationally too expensive and are lacking information about how certain can we be about their predictions. In the present work, we propose a highly efficient deep-learning surrogate fram...
Preprint
Full-text available
For many engineering applications, such as real-time simulations or control, conventional solution techniques of the underlying nonlinear problems are usually computationally too expensive. In this work, we propose a highly efficient deep-learning surrogate framework that is able to predict the response of hyper-elastic bodies under load. The surro...
Preprint
Full-text available
We present a distributed framework for predicting whether a planned reconfiguration step of a modular robot will mechanically overload the structure, causing it to break or lose stability under its own weight. The algorithm is designed to be executed by the modular robot itself and is based on an distributed iterative solution of mechanical equilib...
Article
Full-text available
This contribution presents the extensions of beam‐to‐beam and beam‐inside‐beam contact schemes of the same authors towards frictional interactions. Since the schemes are based on the beams’ true surfaces (instead of surfaces implicitly deduced from the beams’ centroid lines), the presented enhancements are not only able to account for frictional sl...
Conference Paper
Full-text available
Large-scale 3D autonomous self-reconfigurable modular robots are made of numerous interconnected robotic modules that operate in a close packing. The modules are assumed to have their own CPU and memory, and are only able to communicate with their direct neighbors. As such, the robots embody a special computing architecture: a distributed memory an...
Article
Full-text available
The article “Non-localised contact between beams with circular and elliptical cross-sections”, written by “Marco Magliulo, Jakub Lengiewicz, Andreas Zilian and Lars A. A. Beex”, was originally published Online First without open access. After publication in volume 65, issue 5, page 1247–1266 the authors decided to opt for Open Choice and to make th...
Article
Full-text available
Background and Objective This contribution presents a rapid computational framework to mechanically simulate the insertion of a slender medical instrument in a tubular structure such as an artery, the cochlea or another slender instrument. Methods Beams are employed to rapidly simulate the mechanical behaviour of the medical instrument and the tubu...
Preprint
Full-text available
Solid contacts involving soft materials are important in mechanical engineering or biomechanics. Experimentally, such contacts have been shown to shrink significantly under shear, an effect which is usually explained using adhesion models. Here we show that quantitative agreement with recent experiments can be obtained, with no adjustable parameter...
Article
Full-text available
The key novelty of this contribution is a dedicated technique to efficiently determine the distance (gap) function between parallel or almost parallel beams with circular and elliptical cross-sections. The technique consists of parametrizing the surfaces of the two beams in contact, fixing a point on the centroid line of one of the beams and search...
Presentation
We present a method based on Discrete Element Method (DEM) to modeling the Vacuum Packed Particles(VPP)—a class of smart materials/smart structures. Mechanical properties of VPP can be simply adjusted bycontrolling the underpressure, which makes the structures very interesting from practical point of view, givingraise to numerous applications, incl...
Article
Full-text available
This review summarizes recent advances in the area of tribology based on the outcome of a Lorentz Center workshop surveying various physical, chemical and mechanical phenomena across scales. Among the main themes discussed were those of rough surface representations, the breakdown of continuum theories at the nano- and micro-scales, as well as mult...
Article
Full-text available
In this paper, we present a novel approach to modeling and analysis of Vacuum Packed Particle dampers (VPP dampers) with the use of Discrete Element Method (DEM). VPP dampers are composed of loose granular medium encapsulated in a hermetic envelope, with controlled pressure inside the envelope. By changing the level of underpressure inside the enve...
Article
Full-text available
The role of contact pressure on skin friction has been documented in multiple experimental studies. Skin friction significantly raises in the low-pressure regime as load increases while, after a critical pressure value is reached, the coefficient of friction of skin against an external surface becomes mostly insensitive to contact pressure. However...
Article
Full-text available
The original version of this article unfortunately contained a mistake. The presentation of Eq. (6) was incorrect in the original version of this article. The denominator corresponding to the described κ0 contains the coefficient “4” that should be “6”.
Conference Paper
Full-text available
We discuss selected mechanical aspects of self-reconfiguration of densely-packed modular robots. The change of connection topology and transport of modules are fundamental mechanisms for these systems, which determine their desired emergent behavior, e.g., movement, shape change or interaction with their surroundings. At the same time, reconfigurat...
Article
Full-text available
Due to its multifactorial nature, skin friction remains a multiphysics and multiscale phenomenon poorly understood despite its relevance for many biomedical and engineering applications (from superficial pressure ulcers, through shaving and cosmetics, to automotive safety and sports equipment). For example, it is unclear whether, and in which measu...
Conference Paper
Full-text available
Module localization is an important aspect of the operation of self-reconfigurable robots. The knowledge of spatial positions of modules, or at least of the overall shape which the modules form, is the usual prerequisite for reconfiguration planning. We present a general, decentralized algorithm for determining the positions of modules placed on a...
Article
Soft elastohydrodynamic lubrication regime is typical for many elastomeric and biological contacts. As one or both contacting bodies are then highly compliant, relatively low contact pressures may lead to large deformations which are neglected in the classical EHL theory. In the paper, the related finite-deformation effects are studied for two repr...
Conference Paper
Full-text available
A collective actuator is a self-reconfigurable modular-robotic structure which produces useful mechanical work through simultaneous reconfiguration of its constituent units. An actuator is additionally called scalable if its force-to-weight ratio does not depend on the number of its member modules. In this work, we consider scalable collective actu...
Article
Computational contact homogenization approach is applied to study friction anisotropy resulting from asperity interaction in elastic contacts. Contact of rough surfaces with anisotropic roughness is considered with asperity contact at the micro scale being governed by the isotropic Coulomb friction model. Application of a micro-to-macro scale trans...
Conference Paper
Full-text available
The term Programmable Matter (PM) describes the class of future meta-materials of programmable and controllable properties and behavior, e.g., able to autonomously transform into an arbitrary shape. The robotic approaches towards PM are based on the concept of cooperation of millions of micro-robots (modules), acting at a very fine length-scale and...
Article
A mixed formulation of the mass-conserving cavitation model is developed. The cavitation problem is formulated in terms of the hydrodynamic pressure and a complementary variable representing the void fraction in the cavitation zone. Weak form of the mass-balance equation is consistently derived, and it exhibits subtle differences with respect to th...
Article
A computationally efficient model of evolution of contact and wear is developed for a general periodic pin-on-flat problem with the focus on the pin-on-disc configuration and Archard wear model. The evolving contact state is assumed to be fully controlled by the wear process except during a short initial transient period controlled by both wear and...
Article
A finite deformation contact problem with friction and wear is studied in which the shape changes due to wear are finite. Accordingly, in addition to the initial configuration and the current configuration, an intermediate time-dependent configuration is introduced that corresponds to the undeformed body of the shape changed due to wear. Two time s...
Article
The aim of this paper is to present a general method for automation of finite element formulations of large deformation contact problems. A new automatic-differentiation-based notation is introduced that represents a bridge between the classical mathematical notation of contact mechanics and the actual computer implementation of contact finite elem...
Article
Direct differentiation method of sensitivity analysis is developed for frictional contact problems. As a result of the augmented Lagrangian treatment of contact constraints, the direct problem is solved simultaneously for the displacements and Lagrange multipliers using the Newton method. The main purpose of the paper is to show that this formulati...
Chapter
Full-text available
Sensitivity analysis (SA) is developed for three-dimensional multi-body frictional contact problems. The direct differentiation method (DDM) is applied to obtain response sensitivities with respect to arbitrary design parameters (parameter and shape SA). The FE formulation of contact employs smoothing of the master surface, and the augmented Lagran...
Chapter
Complex 3D contact formulations, including various types of smoothing, advanced friction laws and sensitivity analysis have become computationally progressively expensive and, for moderate size problems, can be the main obstacle for practical application of these formulations. The aim of the paper is to present a general symbolic description of con...
Article
Full-text available
Sensitivity analysis (SA) is developed for 2D and 3D multi-body frictional contact problems. The direct differentiation method (DDM) is applied to obtain response sensitivities with respect to arbitrary design parameters (parameter and shape SA). The FE formulation of contact employs smoothing of the master surface, and the augmented Lagrangian tec...
Article
Full-text available
A general class of frictional contact problems with wear is considered in which both the deformation due to contact interactions and shape changes due to wear are finite (i.e. not assumed to be infinitesimal). A theoretical framework is provided on the continuum level, allowing consistent time and spatial discretization. Moreover, with some assumpt...

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Projects

Projects (3)
Project
Modeling Vacuum Packed Particles using Discrete Element Method with Yade DEM software.
Project
The project concerns a futuristic, not yet existing technology of shape shifting systems. The analyzed systems, also known as programmable matter (PM), can be classified as special meta-materials, composed of microscopic, active modules, which are able to process and exchange information, reconnect and move with respect to their neighbours. When appropriately designed and programmed, the objects made of interconnected modules will possibly be able to change their shapes or other physical properties. The aim of the project is to develop effective distributed schemes for reconfiguration planning, which would take into account constraints of both geometrical and mechanical nature.
Archived project
The purpose of the project is to make progress in the modelling and control of programmable matter (PM) - a class of future meta-materials, composed of microscopic active modules. Through proper programming of the modules, objects made of PM could potentially change shape, vary their physical properties, or actively respond to environmental stimuli.