Adam Dacko | Warsaw University of Technology (original) (raw)
Papers by Adam Dacko
International Journal of Non-Linear Mechanics, 1989
Abstract The vertical large-deflection and stability behaviour of spherical inflatables subjected... more Abstract The vertical large-deflection and stability behaviour of spherical inflatables subjected to ring loads concentric around the apex is analysed. Two kinds of loads, those in which the ring is attached to the membrane and a second type in which sliding of the ring relative to the membrane is permitted, are treated. A number of new features, including contact between portions of the membrane inside and outside the ring, wrinkling both within and outside the ring load, and the possibility of the load sliding relative to the membrane, are examined and their effect on the overall behaviour of the structure evaluated. The results are compared, where approriate, with those for the concentrated and rigid plate loads.
Engineering Structures, 1989
Using a revised formulation and solution technique as well as increased numerical accuracy, previ... more Using a revised formulation and solution technique as well as increased numerical accuracy, previous results for the large-deflection and stability behaviour of high-profiled spherical inflatables subjected to an axisymmetric concentrated load are extended, taking into account also the effects of wrinkling in the support region. In addition, the nonlinear behaviour of spherical pneumatics subjected to axisymmetric rigid plate and rigid cylinder loads is treated, again considering effects of wrinkling in both the load and the support zone. These results are compared with those for the concentrated load case and the differences in behaviour from a design point of view are highlighted.
... Dr in˝. Anna Bie jest pracownikiem Uniwersytetu War-misko-Mazurskiego w Olsztynie, dr in˝. ... more ... Dr in˝. Anna Bie jest pracownikiem Uniwersytetu War-misko-Mazurskiego w Olsztynie, dr in˝. Adam Dacko i prof. ... ¼ Warianty i modele obliczeniowe Obliczenia wykonano dla dwóch opisanych ni˝ej wariantów dzia∏ania wiàzki laserowej odpowiednio na dwie ró˝ne próbki. ...
Biuletyn Wojskowej Akademii Technicznej, 2004
Thin-Walled Structures, 1989
Abstract The vertical deflection behaviour of high-profiled spherical inflatables, subjected to a... more Abstract The vertical deflection behaviour of high-profiled spherical inflatables, subjected to axisymmetric loading and undergoing very large displacements, is affected by constraints caused by the geometry of the structure/support. The effects of such ‘support interference’ on the overall deflection characteristics of such structures is treated and evaluated.
Biuletyn Wojskowej Akademii Technicznej, 2006
Composites materials have attracted a great deal of interest for use in various fields e.g. the t... more Composites materials have attracted a great deal of interest for use in various fields e.g. the transport industry, construction, sport equipment and even home applications. This is due to the excellent properties of composite materials such as their high strength/stiffness to mass ratio. Nowadays, finite element (FE) modelling allows investigation of the behaviour of composite materials subjected to loading before the production stage. This paper compares the available ways of FE modelling of composite materials: shell, solid shell and solid layered composite modelling in MSC Patran/Nastran software. The aim of this research work was a comparative analysis and determination of the influence of the applied modelling type on the simulation results. Numerous finite element analyses (FEAs) (tensile and bending) of different narrow plate (resembling a slender, beamlike structural member) structure models were performed, i.e. laminated beam and sandwich beam models, with different layups...
Proceedings of the 13th International Scientific Conference, 2017
The problem considered was to develop, synthesize and design a flexible landing gear leg, subject... more The problem considered was to develop, synthesize and design a flexible landing gear leg, subject to some restrictions resulting from requested loads and boundary conditions. The problem was already undertaken by many researchers, e.g. in monographs written by Currey (Aircraft Landing Gear Design: Principles and Practices, 2004, 1) and Thuis (The development of composite landing gear components for aerospace applications, 2004, 2) and in journals and conference papers (Ganorkar and Deshbhratar, Design Optimization of landing gear of an aircraft, 2014, 3; Goyal and Laksminarayan, Design, Analysis and Simulation of a composite main landing gear for a light aircraft, 2002, 4; Yu-xiu et al., The dynamics research on the composite undercarriage of the Unmanned Aerial Vehicle, 2015, 5; Niezgoda et al., Selection of dynamics characteristics for landing gear with the use of numerical model, 2002, 6). It was assumed that two roving “concentrated constant cross-section booms” would be created. FE simulations allowed to determine the flexible leg deformations, stress distribution and Failure Indices (using maximum stress theory) (Spencer, Novel Optimization Strategy for Composite Beam Type Landing Gear for Light Aircraft, 2013, 7). The foam core inset was tested as a means of mass reduction. FE program ANSYS was used for the analysis (Ansys Theory Reference, 2013, 8).
Journal of KONES, 2007
The paper presents the custom design of the add-on shield, consisting of the set of cylindrical t... more The paper presents the custom design of the add-on shield, consisting of the set of cylindrical tube elements, protecting the main structure against the effect of the explosive blast pressure load. The experimental stand was designed and set up, allowing tests of protective structures loaded with pressure blast wave. The key parameter measured in experiments was the influence of protective shield on the deformation of protected structures under blast load. The deformation and strain in the protected plates was measured using strain gauges (ESAM Traveler bridge) with 100 000 Hz sampling. The PWM-14 explosives was used. Three groups of experiments were performed. In the first one the plate is directly loaded by the blast pressure wave originating from explosion in some distance from the plate. In the second type a single energy absorbing element is used on the plate, while in the third – a set of 4 or 5 energy absorbing elements is used on the plate, loaded by blast wave of explosion ...
International Journal of Non-Linear Mechanics, 1988
Abstract Further results on the axisymmetric large-deflection and stability behaviour of spherica... more Abstract Further results on the axisymmetric large-deflection and stability behaviour of spherical pneumatics subjected to a vertical concentrated load applied at the apex are presented. In particular, the effect of the extensibility on the membrane's behaviour is evaluated. For very high profiled structures, wrinkling at and next to the support is admitted, treating both the case in which a horizontal surface is present at the level of the supports as well as the “stove-pipe-like” support, in which the membrane deflects and wrinkles in a particular manner at the base above a certain load value. Finally, discontinuities in the load-deflection curves, resulting from insufficient accuracy in our earlier numerical work, are eliminated.
Journal of KONES Powertrain and Transport, 2010
The most important task in tests of resistance of aircraft structures to the terrorist threats is... more The most important task in tests of resistance of aircraft structures to the terrorist threats is to determine the sensitivity of thin-walled structures to the blast wave load. For obvious reasons, full-scale experimental investigations are carried out excep tionally. In such cases numerical analyses are very important. They allow tuning model parameters for proper correlation with experimental data. With this preliminary analysis experiment can be planned properly. The paper presents a summary of the results of numerical analysis of ...
Aircraft Engineering and Aerospace Technology, 2018
Purpose This paper aims to present the assumptions, analysis and sample results of numerical mode... more Purpose This paper aims to present the assumptions, analysis and sample results of numerical modeling and analysis of dynamic events encountered in emergency cases during deployment of parachute rescue system (PRS) and hard landing of a small gyrocopter. The optimal design requires knowledge of structural loads and structural response – the information obtained often from experiment. Numerical simulation is presented as an alternative tool for estimating these data. Design/methodology/approach Structural analyses were performed using MSC.Nastran. Multibody simulations were done using MADYMO system. Findings Initial design parameters were evaluated and verified in numerical simulations. Some of the resulting conclusions were proven during the test flights. Practical implications Some chosen results of simulation of dynamic problems are presented. They can be useful as reference values for similar cases for light aircraft analysis. Originality/value The paper presents an alternative w...
Journal of KONES, 2007
The paper presents the problems of modeling cylindrical specimens, loaded by pressure wave from t... more The paper presents the problems of modeling cylindrical specimens, loaded by pressure wave from the blast of explosive charge. The numerical simulation was performed using MSC.Dytran. The cylindrical specimen, along with top and bottom disks is modeled using solid elements. The influence of chosen parameters on the deformation process was investigated. That included material models, hourglass energy damping, rigid/deformable base models and cylinder –top disk connection model (contact/weld). The test rig was setup in numerical model. It consisted of rigid base and the base plate resting on it. The model of set of five energy absorbing cylinders was created. The load was modeled by applying a varying pressure to the top cover of the set. The pressure was applied to the whole top cover or to the chosen area in the middle of the top cover. The results of numerical simulation was compared to the results of experiments. In the case of load applied to the part of top cover, the deformatio...
The paper presents the stand for experimental investigation of cylindrical specimens, loaded by t... more The paper presents the stand for experimental investigation of cylindrical specimens, loaded by the pressure wave of the blast. The key parameters determined in experiment were the duration and the peak value of the load. The blast load was generated by detonation of small explosive charges of PWM-14. The force was measured using piezoelectric gauge and registered by digital oscilloscope. The load acting on the gauge was generated by detonation of the charge situated 150 mm and 200 mm from the gauge and the charge situated just on the cylindrical specimen. The pressure blast wave was transmitted to the specimen using a typical setup: the specimen, covering disk, distance layer (15 mm of Styrofoam), explosive charge. The specimen and the covering disc were either just in contact or were soldered. The explosive charge mass, necessary to crush the specimen, was measured. The time variation of the gauge load was monitored for both aerial explosion, as well as explosion acting directly o...
Photonics Applications in Astronomy, Communications, Industry, and High-Energy Physics Experiments 2019
Journal of KONES Powertrain and Transport, 2010
The most important task in tests of resistance of aircraft structures to the terrorist threats is... more The most important task in tests of resistance of aircraft structures to the terrorist threats is to determine the sensitivity of thin-walled structures to the blast wave load. For obvious reasons, full-scale experimental investigations are carried out exceptionally. In such cases numerical analyses are very important. They allow tuning model parameters for proper correlation with experimental data. With this preliminary analysis experiment can be planned properly. The paper presents a summary of the results of numerical analysis of model of medium size fuselage. Various manufacturing techniques are considered – the skin made of aluminum alloy (2024-T3) and the skins made of modern layered materials (GLARE) were compared. Characteristics of the materials used in FE simulations were obtained experimentally. Modeling of C4 detonation was also discussed. Studies have shown very strong sensitivity of the results to chosen numerical models of materials, formulations of elements, assumed ...
Theoretical & Applied Science, 2015
International Journal of Non-Linear Mechanics, 1989
Abstract The vertical large-deflection and stability behaviour of spherical inflatables subjected... more Abstract The vertical large-deflection and stability behaviour of spherical inflatables subjected to ring loads concentric around the apex is analysed. Two kinds of loads, those in which the ring is attached to the membrane and a second type in which sliding of the ring relative to the membrane is permitted, are treated. A number of new features, including contact between portions of the membrane inside and outside the ring, wrinkling both within and outside the ring load, and the possibility of the load sliding relative to the membrane, are examined and their effect on the overall behaviour of the structure evaluated. The results are compared, where approriate, with those for the concentrated and rigid plate loads.
Engineering Structures, 1989
Using a revised formulation and solution technique as well as increased numerical accuracy, previ... more Using a revised formulation and solution technique as well as increased numerical accuracy, previous results for the large-deflection and stability behaviour of high-profiled spherical inflatables subjected to an axisymmetric concentrated load are extended, taking into account also the effects of wrinkling in the support region. In addition, the nonlinear behaviour of spherical pneumatics subjected to axisymmetric rigid plate and rigid cylinder loads is treated, again considering effects of wrinkling in both the load and the support zone. These results are compared with those for the concentrated load case and the differences in behaviour from a design point of view are highlighted.
... Dr in˝. Anna Bie jest pracownikiem Uniwersytetu War-misko-Mazurskiego w Olsztynie, dr in˝. ... more ... Dr in˝. Anna Bie jest pracownikiem Uniwersytetu War-misko-Mazurskiego w Olsztynie, dr in˝. Adam Dacko i prof. ... ¼ Warianty i modele obliczeniowe Obliczenia wykonano dla dwóch opisanych ni˝ej wariantów dzia∏ania wiàzki laserowej odpowiednio na dwie ró˝ne próbki. ...
Biuletyn Wojskowej Akademii Technicznej, 2004
Thin-Walled Structures, 1989
Abstract The vertical deflection behaviour of high-profiled spherical inflatables, subjected to a... more Abstract The vertical deflection behaviour of high-profiled spherical inflatables, subjected to axisymmetric loading and undergoing very large displacements, is affected by constraints caused by the geometry of the structure/support. The effects of such ‘support interference’ on the overall deflection characteristics of such structures is treated and evaluated.
Biuletyn Wojskowej Akademii Technicznej, 2006
Composites materials have attracted a great deal of interest for use in various fields e.g. the t... more Composites materials have attracted a great deal of interest for use in various fields e.g. the transport industry, construction, sport equipment and even home applications. This is due to the excellent properties of composite materials such as their high strength/stiffness to mass ratio. Nowadays, finite element (FE) modelling allows investigation of the behaviour of composite materials subjected to loading before the production stage. This paper compares the available ways of FE modelling of composite materials: shell, solid shell and solid layered composite modelling in MSC Patran/Nastran software. The aim of this research work was a comparative analysis and determination of the influence of the applied modelling type on the simulation results. Numerous finite element analyses (FEAs) (tensile and bending) of different narrow plate (resembling a slender, beamlike structural member) structure models were performed, i.e. laminated beam and sandwich beam models, with different layups...
Proceedings of the 13th International Scientific Conference, 2017
The problem considered was to develop, synthesize and design a flexible landing gear leg, subject... more The problem considered was to develop, synthesize and design a flexible landing gear leg, subject to some restrictions resulting from requested loads and boundary conditions. The problem was already undertaken by many researchers, e.g. in monographs written by Currey (Aircraft Landing Gear Design: Principles and Practices, 2004, 1) and Thuis (The development of composite landing gear components for aerospace applications, 2004, 2) and in journals and conference papers (Ganorkar and Deshbhratar, Design Optimization of landing gear of an aircraft, 2014, 3; Goyal and Laksminarayan, Design, Analysis and Simulation of a composite main landing gear for a light aircraft, 2002, 4; Yu-xiu et al., The dynamics research on the composite undercarriage of the Unmanned Aerial Vehicle, 2015, 5; Niezgoda et al., Selection of dynamics characteristics for landing gear with the use of numerical model, 2002, 6). It was assumed that two roving “concentrated constant cross-section booms” would be created. FE simulations allowed to determine the flexible leg deformations, stress distribution and Failure Indices (using maximum stress theory) (Spencer, Novel Optimization Strategy for Composite Beam Type Landing Gear for Light Aircraft, 2013, 7). The foam core inset was tested as a means of mass reduction. FE program ANSYS was used for the analysis (Ansys Theory Reference, 2013, 8).
Journal of KONES, 2007
The paper presents the custom design of the add-on shield, consisting of the set of cylindrical t... more The paper presents the custom design of the add-on shield, consisting of the set of cylindrical tube elements, protecting the main structure against the effect of the explosive blast pressure load. The experimental stand was designed and set up, allowing tests of protective structures loaded with pressure blast wave. The key parameter measured in experiments was the influence of protective shield on the deformation of protected structures under blast load. The deformation and strain in the protected plates was measured using strain gauges (ESAM Traveler bridge) with 100 000 Hz sampling. The PWM-14 explosives was used. Three groups of experiments were performed. In the first one the plate is directly loaded by the blast pressure wave originating from explosion in some distance from the plate. In the second type a single energy absorbing element is used on the plate, while in the third – a set of 4 or 5 energy absorbing elements is used on the plate, loaded by blast wave of explosion ...
International Journal of Non-Linear Mechanics, 1988
Abstract Further results on the axisymmetric large-deflection and stability behaviour of spherica... more Abstract Further results on the axisymmetric large-deflection and stability behaviour of spherical pneumatics subjected to a vertical concentrated load applied at the apex are presented. In particular, the effect of the extensibility on the membrane's behaviour is evaluated. For very high profiled structures, wrinkling at and next to the support is admitted, treating both the case in which a horizontal surface is present at the level of the supports as well as the “stove-pipe-like” support, in which the membrane deflects and wrinkles in a particular manner at the base above a certain load value. Finally, discontinuities in the load-deflection curves, resulting from insufficient accuracy in our earlier numerical work, are eliminated.
Journal of KONES Powertrain and Transport, 2010
The most important task in tests of resistance of aircraft structures to the terrorist threats is... more The most important task in tests of resistance of aircraft structures to the terrorist threats is to determine the sensitivity of thin-walled structures to the blast wave load. For obvious reasons, full-scale experimental investigations are carried out excep tionally. In such cases numerical analyses are very important. They allow tuning model parameters for proper correlation with experimental data. With this preliminary analysis experiment can be planned properly. The paper presents a summary of the results of numerical analysis of ...
Aircraft Engineering and Aerospace Technology, 2018
Purpose This paper aims to present the assumptions, analysis and sample results of numerical mode... more Purpose This paper aims to present the assumptions, analysis and sample results of numerical modeling and analysis of dynamic events encountered in emergency cases during deployment of parachute rescue system (PRS) and hard landing of a small gyrocopter. The optimal design requires knowledge of structural loads and structural response – the information obtained often from experiment. Numerical simulation is presented as an alternative tool for estimating these data. Design/methodology/approach Structural analyses were performed using MSC.Nastran. Multibody simulations were done using MADYMO system. Findings Initial design parameters were evaluated and verified in numerical simulations. Some of the resulting conclusions were proven during the test flights. Practical implications Some chosen results of simulation of dynamic problems are presented. They can be useful as reference values for similar cases for light aircraft analysis. Originality/value The paper presents an alternative w...
Journal of KONES, 2007
The paper presents the problems of modeling cylindrical specimens, loaded by pressure wave from t... more The paper presents the problems of modeling cylindrical specimens, loaded by pressure wave from the blast of explosive charge. The numerical simulation was performed using MSC.Dytran. The cylindrical specimen, along with top and bottom disks is modeled using solid elements. The influence of chosen parameters on the deformation process was investigated. That included material models, hourglass energy damping, rigid/deformable base models and cylinder –top disk connection model (contact/weld). The test rig was setup in numerical model. It consisted of rigid base and the base plate resting on it. The model of set of five energy absorbing cylinders was created. The load was modeled by applying a varying pressure to the top cover of the set. The pressure was applied to the whole top cover or to the chosen area in the middle of the top cover. The results of numerical simulation was compared to the results of experiments. In the case of load applied to the part of top cover, the deformatio...
The paper presents the stand for experimental investigation of cylindrical specimens, loaded by t... more The paper presents the stand for experimental investigation of cylindrical specimens, loaded by the pressure wave of the blast. The key parameters determined in experiment were the duration and the peak value of the load. The blast load was generated by detonation of small explosive charges of PWM-14. The force was measured using piezoelectric gauge and registered by digital oscilloscope. The load acting on the gauge was generated by detonation of the charge situated 150 mm and 200 mm from the gauge and the charge situated just on the cylindrical specimen. The pressure blast wave was transmitted to the specimen using a typical setup: the specimen, covering disk, distance layer (15 mm of Styrofoam), explosive charge. The specimen and the covering disc were either just in contact or were soldered. The explosive charge mass, necessary to crush the specimen, was measured. The time variation of the gauge load was monitored for both aerial explosion, as well as explosion acting directly o...
Photonics Applications in Astronomy, Communications, Industry, and High-Energy Physics Experiments 2019
Journal of KONES Powertrain and Transport, 2010
The most important task in tests of resistance of aircraft structures to the terrorist threats is... more The most important task in tests of resistance of aircraft structures to the terrorist threats is to determine the sensitivity of thin-walled structures to the blast wave load. For obvious reasons, full-scale experimental investigations are carried out exceptionally. In such cases numerical analyses are very important. They allow tuning model parameters for proper correlation with experimental data. With this preliminary analysis experiment can be planned properly. The paper presents a summary of the results of numerical analysis of model of medium size fuselage. Various manufacturing techniques are considered – the skin made of aluminum alloy (2024-T3) and the skins made of modern layered materials (GLARE) were compared. Characteristics of the materials used in FE simulations were obtained experimentally. Modeling of C4 detonation was also discussed. Studies have shown very strong sensitivity of the results to chosen numerical models of materials, formulations of elements, assumed ...
Theoretical & Applied Science, 2015