Piotr Lacki - Academia.edu (original) (raw)

Papers by Piotr Lacki

Computers & Structures, 2021

Abstract The work presents the parametric study of a steel–concrete composite beam with composite... more Abstract The work presents the parametric study of a steel–concrete composite beam with composite dowel connectors. The designed beam is located in a highly loaded warehouse ceiling with a useful load of 20 kN/m2. In the first part of the work, the best solution of the composite dowel beam was selected from among 7 variants. The parameterization of the composite beam was made on the basis of the following parameters determined by numerical calculations: mass of the steel part, vertical deflection of the beam, stresses in the steel and concrete, and the character of concrete cracks. Then in the second part of the work, the best variant of the beam with composite dowels was compared with the commonly used solution of a composite steel–concrete beam with headed stud connectors. In the numerical model, the finite element method was used to describe the influence of mechanical loads on the strains and stresses in the floor beam. Numerical calculations were made using the ADINA System based on FEM. A model was built from 3D-solid elements. However, the reinforcing bars were modelled with truss elements (rebar elements). The applied boundary conditions reflected the freely supported composite beam. The advanced concrete model available in the ADINA System program was used to simulate concrete, assessing the possibility of concrete cracking.

Composite Structures, 2018

The paper presents the influence of PU foam on the buckling resistance of an I-beam made with she... more The paper presents the influence of PU foam on the buckling resistance of an I-beam made with sheets aluminum alloy 6061-T6 sheets and GFRP plates. Four beam types were considered: an aluminum beam, a composite aluminum-fiberglass beam, a composite aluminum-fiberglass-PU beam and a composite aluminum-fiberglass-PU-ribs beam. Each beam was made with two C-profiles connected by webs, with flanges reinforced by flat bars. Channels were made by bending 0.8 mm thick aluminum alloy 6061-T6 sheets. Flat bars were made from aluminum alloy 6061-T6 2.0 mm in thickness. The metal sheets components were connected by Refill Friction Stir Spot Welding RFSSW technology. The composite aluminum-fiberglass beam additionally has GFRP plates glued to the flanges. The 3.0 mm thick GFRP plates were connected by a polyurethane adhesive. The composite aluminum-GFRP-PU and aluminum-GFRP-PU-ribs beams have a rectangular cross-section. The composite aluminum-GFRP-PU beam was made like the composite aluminum-GFRP beam, but with stiffening of the web by polyurethane foam. The aluminum-GFRP-PU-ribs beam was made like the composite aluminum-GFRP beam, but with stiffening of the web by aluminum ribs and polyurethane foam. The PU foam filled up the I-sections in such a way that rectangular cross-sections were obtained. The beams were subjected to three-point bending tests.

Metoda elementów skończonych, chirurgia małoinwazyjna, narzędzia laparoskopowe, nożyczki laparosk... more Metoda elementów skończonych, chirurgia małoinwazyjna, narzędzia laparoskopowe, nożyczki laparoskopowe. Streszczenie W pracy przedstawiono wyniki analizy numerycznej wytypowanej postaci konstrukcyjnej nożyczek laparoskopowych z wykorzystaniem metody elementów skończonych. W szczególności przedstawiono rozkład naprężeń zredukowanych w poszczególnych elementach nożyczek dla kolejnych etapów ich obciążania. Wyniki analizy stanowią wytyczne do optymalizacji kształtu nożyczek i poprawy ich własności eksploatacyjnych. Wprowadzenie Chirurgia małoinwazyjna z zastosowaniem technik endoskopowych jest obecnie najintensywniej rozwijającym się kierunkiem chirurgii. Jeszcze kilkanaście lat temu techniki endoskopowe wykorzystywane były wyłącznie w celach diagnostycznych. Obecnie znajdują zastosowanie w każdej dziedzinie chirurgii. Stosowane są takie techniki endoskopowe, jak laparoskopia, gastroskopia, kolonoskopia, rektoskopia, artroskopia, cystoskopia, bronchoskopia [1-3].

Scientific Research of the Institute of Mathematics and Computer Science, 2012

Optimization of the dogboning phenomenon of the coronary artery stent is the aim of the paper. Th... more Optimization of the dogboning phenomenon of the coronary artery stent is the aim of the paper. The mathematical model for the slotted tube stent is formulated with the finite element analysis based on a parametric geometric model of stent. Some of the mechanical properties are examined: the expanding pressure, plastic strain, foreshortening and dogboning. This paper is focused on determination of the optimal parameters for lowest dogboning.

Archives of Metallurgy and Materials, 2019

This work presents a numerical simulation of aviation structure joined by friction stir welding, ... more This work presents a numerical simulation of aviation structure joined by friction stir welding, FSW, process. The numerical simulation of aviation structure joined by FSW was created. The simulation uses thermomechanical coupled formulation. The model required creation of finite elements representing sheets, stiffeners and welds, definition of material models and boundary conditions. The thermal model took into account heat conduction and convection assigned to appropriate elements of the structure. Time functions were applied to the description of a heat source movement. The numerical model included the stage of welding and the stage of releasing clamps. The output of the simulation are residual stresses and deformations occurring in the panel. Parameters of the global model (the panel model) were selected based on the local model (the single joint model), the experimental verification of the local model using the single joint and the geometry of the panel joints.

Friction stir welding is one of the newest methods of material joining. It is constantly develope... more Friction stir welding is one of the newest methods of material joining. It is constantly developed and Refill Friction Stir Spot Welding (RFSSW) is one of its varieties. RFSSW is a solid-state joining technology. During the process, heat is generated as a result of friction between the tool and the joined materials as well as the material plastic deformation. RFSSW uses a rotating tool consisting of probe, sleeve and clamping ring [1]. RFSSW joints are produced in two ways. The difference between them is in the way the probe and sleeve plunge into the joined materials. In the first method the probe is plunged into the workpieces, but the sleeve is retracted. At the same time, the welded material is transferred to the sleeve location. Upon reaching the desired plunge depth, the tool is kept in that position. After that, the rotating probe is retracted from the welded joint and the material is pressed into the welded point by the sleeve. In the second method, the sleeve is plunged int...

Materials, 2020

The study presents the results of examinations of wear in tools made of 1.2344 steel without and ... more The study presents the results of examinations of wear in tools made of 1.2344 steel without and with an anti-wear coating in the process of welding overlap joints of sheet metal made of 7075-T6 aluminum alloy using friction stir welding (FSW) technology. A commercial anti-wear AlCrN coating (Balinit® Alcrona Pro by Oerlikon Balzers Coating Poland Sp. z o.o., Polkowice, Poland) was examined, applied using physical vapor deposition (PVD) and used to improve tool life in metalworking processes. Wear tests for the tools were conducted in industrial conditions at specific parameters of the friction stir welding process. Tool wear was evaluated through examination of the tool working surface. The results of the static tensile strength tests and metallographic examinations of the joints were used to evaluate the effect of tool wear and the coating impact on joint quality. The results obtained in the study show that the tool made of 1.2344 steel was intensively worn after the welding of a ...

Archives of Metallurgy and Materials, 2017

The paper concerns aluminum joints made using friction stir welding. Although in the aerospace in... more The paper concerns aluminum joints made using friction stir welding. Although in the aerospace industry there is a tendency to replace metal components with composites, aluminum continues to be a valuable material. Its share in the aircraft structures is the biggest among all structural metals. Lots of aluminum components are made of sheets and most of them require joining. Friction stir welding is a relatively new joining technology, particularly with regard to the sheets having a thickness of 1 mm or lower. The paper is dedicated to non-destructive testing of such joints using ultrasonic inspection. It was found that ultrasonic testing allows for distinguishing between joints without material discontinuities, joint with material discontinuities at the advancing side and joint with discontinuities extending through the whole width of the stir zone. During research only horizontally aligned defects were taken into account.

Civil and Environmental Engineering Reports, 2017

The aim of the work was to perform numerical analysis of a steel-concrete composite floor located... more The aim of the work was to perform numerical analysis of a steel-concrete composite floor located in a LIPSK type building. A numerical model of the analytically designed floor was performed. The floor was in a six-storey, retail and service building. The thickness of a prefabricated slab was 100 mm. The two-row, crisscrossed reinforcement of the slab was made from φ16 mm rods with a spacing of 150 x 200 mm. The span of the beams made of steel IPE 160 profiles was 6.00 m and they were spaced every 1.20 m. The steelconcrete composite was obtained using 80×16 Nelson fasteners. The numerical analysis was carried out using the ADINA System based on the Finite Element Method. The stresses and strains in the steel and concrete elements, the distribution of the forces in the reinforcement bars and cracking in concrete were evaluated. The FEM model was made from 3D-solid finite elements (IPE profile and concrete slab) and truss elements (reinforcement bars). The adopted steel material model...

Eksploatacja i Niezawodność – Maintenance and Reliability, 2018

The study presents an analysis of wear of tools made of 1.2344 steel and MP159 alloy for the proc... more The study presents an analysis of wear of tools made of 1.2344 steel and MP159 alloy for the process of obtaining an overlap joint in 1.0 mm and 0.8 mm sheet metal made of 7075 T6 aluminum alloy using friction stir welding (FSW) technology. Tool geometry was designed at the Czestochowa University of Technology. Evaluation of tool wear was conducted based on the measurements of geometry of working area of tools by means of a multisensory meter system and based on the assessment of the working area by means of a stereoscope after individual stages of wear tests. Furthermore, based on the results of a static tensile strength test and metallographic examinations of the specimens sampled from the joints obtained during tool wear tests, the effect of the degree of tool wear on joint quality was also evaluated. Analysis of the results revealed that both the tool made of 1.2344 steel and that made of MP159 alloy were substantially worn, increasing the risk of further use of the tools for th...

Civil and Environmental Engineering Reports, 2017

The work presents a brief description of VFT-WIB® steel-concrete composite beams, examples of com... more The work presents a brief description of VFT-WIB® steel-concrete composite beams, examples of composite dowel shear connection shapes are presented. A steel-concrete bridge girder construction solution for the new shape of composite dowel shear connection was proposed. The geometric parameters of the steel section web cutting line are given. For the assumed cross-section dimensions, a numerical model of the girder was made. Numerical analysis was performed, the results of which were compared with the results of the analytical calculations. A program of actions aimed at further optimization of the model is presented.

Zeszyty Naukowe Politechniki Częstochowskiej. Budownictwo, 2017

Jednym ze sposobów konstruowania przęseł mostów średniej rozpiętości jest stosowanie zespolonych ... more Jednym ze sposobów konstruowania przęseł mostów średniej rozpiętości jest stosowanie zespolonych dźwigarów stalowo-betonowych typu VFT, które przedstawiono między innymi w pracach [1, 2]. W rozwiązaniu tym stalowa blachownica spawana prefabrykowana jest wraz z półką żelbetową, stanowiącą jednocześnie deskowanie dla monolitycznej płyty pomostu, betonowanej podczas montażu. Zespolenie belki z płytą zapewnione jest za pomocą łączników sworzniowych (rys. 1).

Archives of Metallurgy and Materials, 2015

Despite substantial demand for drawn parts made of high-strength sheet metal (including titanium ... more Despite substantial demand for drawn parts made of high-strength sheet metal (including titanium alloys) observed in the modern industry, particularly automotive and aviation, their application remains insignificant. This results from the fact that such sheet metal shows poor plasticity and its cold-forming is almost impossible. Low drawability makes it impossible to obtain even such simple shapes as spherical cups. The authors of this study developed circular sheet-metal blanks with cutouts on their perimeter. The blanks allow for cold forming of spherical cups from Ti6Al4V titanium alloy sheet metal using conventional rigid tools. The cutouts proposed in the study affect plastic strain distribution, which in turn leads to an increase in forming depth by about 30%. The numerical analysis, performed using the PamStamp 2G System software based on finite element method, was verified experimentally.

Archives of Metallurgy and Materials, 2017

One of the important parameters of Refill Friction Stir Spot Welding is the so-called basic posit... more One of the important parameters of Refill Friction Stir Spot Welding is the so-called basic position of the tool. This is the arrangement of the pin and sleeve which occurs when the tool is plunged into the material. The basic positions can be divided into two categories. In the first category, the sleeve and the pin are above the sheet surface or below sheet surface and in the second category the pin is retracted within the sleeve or protrudes from it.The aim of the work was to test four settings of the basic position, and then determine the best setting of the basic position, without changing the other welding parameters. Joints made of an aluminum alloy 2024-T3 sheet having a thickness of 1.0 mm and an aluminum alloy D16UTW sheet having a thickness of 0.6 mm were analysed. The best setting of the basic position was determined based on assessment of the force carried in shear test, macrostructure and weld face of the joints.

Key Engineering Materials, 2016

The paper presents an analysis of load capacity for welded specimens made of titanium Grade 5 of ... more The paper presents an analysis of load capacity for welded specimens made of titanium Grade 5 of 0.8 mm thickness. The lap joins were made by Resistance Spot Welding (RSW). The load capacity for joints with a single spot were assessed. The joints were welded with 5 variants of welding parameters. On the basis of the capacity of the joints, the best performance were selected. The best welding parameters were used to make three types of joints with different spacing of the welds: with a single weld, the two welds arranged parallel to the shearing direction and two welds arranged perpendicular to the shearing direction. The load capacity, a plastic strains distribution and a method of cracking were assessed. An example of the feasibility of a beam construction made of titanium grade 5 sheets welded by resistance spot welding were shown.

Archives of Metallurgy and Materials, 2015

The dynamic development of the friction stir welding (FSW) technology is the basis for the design... more The dynamic development of the friction stir welding (FSW) technology is the basis for the design of durabe joints inter alia in the aviation industry. This technology has a prospective application, especially for the aluminum alloys. It is suitable for a broad spectrum of permanent joints. The joints obtained by FSW technology are characterized by good mechanical properties. In this paper, the friction stir spot welding joints were analysed. The example of a structure made using this technology were presented. The lap joints made of 2mm Al 6061-T6 sheets were the investigation subject. The different spot welds arrangements were analysed. The tensile test were performed with optical deformation measurement system, which allow to obtain the plastic deformation field on the sample surface. The plastic strain graphs for the characteristic line passing through the maximum deformation were registered and presented. The experimental results were compared to the FEM numerical analysis. The...

Archives of Metallurgy and Materials, 2015

FSW (Friction Stir Welding) and RFSSW (Refill Friction Stir Spot Welding) joints have been increa... more FSW (Friction Stir Welding) and RFSSW (Refill Friction Stir Spot Welding) joints have been increasingly used in industrial practice. They successfully replace fusion-welded, riveted or resistance-welded joints. In the last two decades, dynamic development of this method has stimulated investigations of the fast methods for joint diagnostics. These methods should be non-destructive and easy to be used in technological processes. The methods of assessment of joint quality are expected to detect discontinuities in the structures welded using FSW and FSSW methods. Reliable detection of flaws would substantially extend the range of applications of FSW joints across many sectors of industry, including aviation. The investigations carried out in this paper allowed for characterization of defects present in FSW and RFSSW joints. Causes of these defects were also stressed. An overview of the methodologies for assessment of joint quality was presented. Results of assessment of the quality of ...

Computers & Structures, 2021

Abstract The work presents the parametric study of a steel–concrete composite beam with composite... more Abstract The work presents the parametric study of a steel–concrete composite beam with composite dowel connectors. The designed beam is located in a highly loaded warehouse ceiling with a useful load of 20 kN/m2. In the first part of the work, the best solution of the composite dowel beam was selected from among 7 variants. The parameterization of the composite beam was made on the basis of the following parameters determined by numerical calculations: mass of the steel part, vertical deflection of the beam, stresses in the steel and concrete, and the character of concrete cracks. Then in the second part of the work, the best variant of the beam with composite dowels was compared with the commonly used solution of a composite steel–concrete beam with headed stud connectors. In the numerical model, the finite element method was used to describe the influence of mechanical loads on the strains and stresses in the floor beam. Numerical calculations were made using the ADINA System based on FEM. A model was built from 3D-solid elements. However, the reinforcing bars were modelled with truss elements (rebar elements). The applied boundary conditions reflected the freely supported composite beam. The advanced concrete model available in the ADINA System program was used to simulate concrete, assessing the possibility of concrete cracking.

Composite Structures, 2018

The paper presents the influence of PU foam on the buckling resistance of an I-beam made with she... more The paper presents the influence of PU foam on the buckling resistance of an I-beam made with sheets aluminum alloy 6061-T6 sheets and GFRP plates. Four beam types were considered: an aluminum beam, a composite aluminum-fiberglass beam, a composite aluminum-fiberglass-PU beam and a composite aluminum-fiberglass-PU-ribs beam. Each beam was made with two C-profiles connected by webs, with flanges reinforced by flat bars. Channels were made by bending 0.8 mm thick aluminum alloy 6061-T6 sheets. Flat bars were made from aluminum alloy 6061-T6 2.0 mm in thickness. The metal sheets components were connected by Refill Friction Stir Spot Welding RFSSW technology. The composite aluminum-fiberglass beam additionally has GFRP plates glued to the flanges. The 3.0 mm thick GFRP plates were connected by a polyurethane adhesive. The composite aluminum-GFRP-PU and aluminum-GFRP-PU-ribs beams have a rectangular cross-section. The composite aluminum-GFRP-PU beam was made like the composite aluminum-GFRP beam, but with stiffening of the web by polyurethane foam. The aluminum-GFRP-PU-ribs beam was made like the composite aluminum-GFRP beam, but with stiffening of the web by aluminum ribs and polyurethane foam. The PU foam filled up the I-sections in such a way that rectangular cross-sections were obtained. The beams were subjected to three-point bending tests.

Metoda elementów skończonych, chirurgia małoinwazyjna, narzędzia laparoskopowe, nożyczki laparosk... more Metoda elementów skończonych, chirurgia małoinwazyjna, narzędzia laparoskopowe, nożyczki laparoskopowe. Streszczenie W pracy przedstawiono wyniki analizy numerycznej wytypowanej postaci konstrukcyjnej nożyczek laparoskopowych z wykorzystaniem metody elementów skończonych. W szczególności przedstawiono rozkład naprężeń zredukowanych w poszczególnych elementach nożyczek dla kolejnych etapów ich obciążania. Wyniki analizy stanowią wytyczne do optymalizacji kształtu nożyczek i poprawy ich własności eksploatacyjnych. Wprowadzenie Chirurgia małoinwazyjna z zastosowaniem technik endoskopowych jest obecnie najintensywniej rozwijającym się kierunkiem chirurgii. Jeszcze kilkanaście lat temu techniki endoskopowe wykorzystywane były wyłącznie w celach diagnostycznych. Obecnie znajdują zastosowanie w każdej dziedzinie chirurgii. Stosowane są takie techniki endoskopowe, jak laparoskopia, gastroskopia, kolonoskopia, rektoskopia, artroskopia, cystoskopia, bronchoskopia [1-3].

Scientific Research of the Institute of Mathematics and Computer Science, 2012

Optimization of the dogboning phenomenon of the coronary artery stent is the aim of the paper. Th... more Optimization of the dogboning phenomenon of the coronary artery stent is the aim of the paper. The mathematical model for the slotted tube stent is formulated with the finite element analysis based on a parametric geometric model of stent. Some of the mechanical properties are examined: the expanding pressure, plastic strain, foreshortening and dogboning. This paper is focused on determination of the optimal parameters for lowest dogboning.

Archives of Metallurgy and Materials, 2019

This work presents a numerical simulation of aviation structure joined by friction stir welding, ... more This work presents a numerical simulation of aviation structure joined by friction stir welding, FSW, process. The numerical simulation of aviation structure joined by FSW was created. The simulation uses thermomechanical coupled formulation. The model required creation of finite elements representing sheets, stiffeners and welds, definition of material models and boundary conditions. The thermal model took into account heat conduction and convection assigned to appropriate elements of the structure. Time functions were applied to the description of a heat source movement. The numerical model included the stage of welding and the stage of releasing clamps. The output of the simulation are residual stresses and deformations occurring in the panel. Parameters of the global model (the panel model) were selected based on the local model (the single joint model), the experimental verification of the local model using the single joint and the geometry of the panel joints.

Friction stir welding is one of the newest methods of material joining. It is constantly develope... more Friction stir welding is one of the newest methods of material joining. It is constantly developed and Refill Friction Stir Spot Welding (RFSSW) is one of its varieties. RFSSW is a solid-state joining technology. During the process, heat is generated as a result of friction between the tool and the joined materials as well as the material plastic deformation. RFSSW uses a rotating tool consisting of probe, sleeve and clamping ring [1]. RFSSW joints are produced in two ways. The difference between them is in the way the probe and sleeve plunge into the joined materials. In the first method the probe is plunged into the workpieces, but the sleeve is retracted. At the same time, the welded material is transferred to the sleeve location. Upon reaching the desired plunge depth, the tool is kept in that position. After that, the rotating probe is retracted from the welded joint and the material is pressed into the welded point by the sleeve. In the second method, the sleeve is plunged int...

Materials, 2020

The study presents the results of examinations of wear in tools made of 1.2344 steel without and ... more The study presents the results of examinations of wear in tools made of 1.2344 steel without and with an anti-wear coating in the process of welding overlap joints of sheet metal made of 7075-T6 aluminum alloy using friction stir welding (FSW) technology. A commercial anti-wear AlCrN coating (Balinit® Alcrona Pro by Oerlikon Balzers Coating Poland Sp. z o.o., Polkowice, Poland) was examined, applied using physical vapor deposition (PVD) and used to improve tool life in metalworking processes. Wear tests for the tools were conducted in industrial conditions at specific parameters of the friction stir welding process. Tool wear was evaluated through examination of the tool working surface. The results of the static tensile strength tests and metallographic examinations of the joints were used to evaluate the effect of tool wear and the coating impact on joint quality. The results obtained in the study show that the tool made of 1.2344 steel was intensively worn after the welding of a ...

Archives of Metallurgy and Materials, 2017

The paper concerns aluminum joints made using friction stir welding. Although in the aerospace in... more The paper concerns aluminum joints made using friction stir welding. Although in the aerospace industry there is a tendency to replace metal components with composites, aluminum continues to be a valuable material. Its share in the aircraft structures is the biggest among all structural metals. Lots of aluminum components are made of sheets and most of them require joining. Friction stir welding is a relatively new joining technology, particularly with regard to the sheets having a thickness of 1 mm or lower. The paper is dedicated to non-destructive testing of such joints using ultrasonic inspection. It was found that ultrasonic testing allows for distinguishing between joints without material discontinuities, joint with material discontinuities at the advancing side and joint with discontinuities extending through the whole width of the stir zone. During research only horizontally aligned defects were taken into account.

Civil and Environmental Engineering Reports, 2017

The aim of the work was to perform numerical analysis of a steel-concrete composite floor located... more The aim of the work was to perform numerical analysis of a steel-concrete composite floor located in a LIPSK type building. A numerical model of the analytically designed floor was performed. The floor was in a six-storey, retail and service building. The thickness of a prefabricated slab was 100 mm. The two-row, crisscrossed reinforcement of the slab was made from φ16 mm rods with a spacing of 150 x 200 mm. The span of the beams made of steel IPE 160 profiles was 6.00 m and they were spaced every 1.20 m. The steelconcrete composite was obtained using 80×16 Nelson fasteners. The numerical analysis was carried out using the ADINA System based on the Finite Element Method. The stresses and strains in the steel and concrete elements, the distribution of the forces in the reinforcement bars and cracking in concrete were evaluated. The FEM model was made from 3D-solid finite elements (IPE profile and concrete slab) and truss elements (reinforcement bars). The adopted steel material model...

Eksploatacja i Niezawodność – Maintenance and Reliability, 2018

The study presents an analysis of wear of tools made of 1.2344 steel and MP159 alloy for the proc... more The study presents an analysis of wear of tools made of 1.2344 steel and MP159 alloy for the process of obtaining an overlap joint in 1.0 mm and 0.8 mm sheet metal made of 7075 T6 aluminum alloy using friction stir welding (FSW) technology. Tool geometry was designed at the Czestochowa University of Technology. Evaluation of tool wear was conducted based on the measurements of geometry of working area of tools by means of a multisensory meter system and based on the assessment of the working area by means of a stereoscope after individual stages of wear tests. Furthermore, based on the results of a static tensile strength test and metallographic examinations of the specimens sampled from the joints obtained during tool wear tests, the effect of the degree of tool wear on joint quality was also evaluated. Analysis of the results revealed that both the tool made of 1.2344 steel and that made of MP159 alloy were substantially worn, increasing the risk of further use of the tools for th...

Civil and Environmental Engineering Reports, 2017

The work presents a brief description of VFT-WIB® steel-concrete composite beams, examples of com... more The work presents a brief description of VFT-WIB® steel-concrete composite beams, examples of composite dowel shear connection shapes are presented. A steel-concrete bridge girder construction solution for the new shape of composite dowel shear connection was proposed. The geometric parameters of the steel section web cutting line are given. For the assumed cross-section dimensions, a numerical model of the girder was made. Numerical analysis was performed, the results of which were compared with the results of the analytical calculations. A program of actions aimed at further optimization of the model is presented.

Zeszyty Naukowe Politechniki Częstochowskiej. Budownictwo, 2017

Jednym ze sposobów konstruowania przęseł mostów średniej rozpiętości jest stosowanie zespolonych ... more Jednym ze sposobów konstruowania przęseł mostów średniej rozpiętości jest stosowanie zespolonych dźwigarów stalowo-betonowych typu VFT, które przedstawiono między innymi w pracach [1, 2]. W rozwiązaniu tym stalowa blachownica spawana prefabrykowana jest wraz z półką żelbetową, stanowiącą jednocześnie deskowanie dla monolitycznej płyty pomostu, betonowanej podczas montażu. Zespolenie belki z płytą zapewnione jest za pomocą łączników sworzniowych (rys. 1).

Archives of Metallurgy and Materials, 2015

Despite substantial demand for drawn parts made of high-strength sheet metal (including titanium ... more Despite substantial demand for drawn parts made of high-strength sheet metal (including titanium alloys) observed in the modern industry, particularly automotive and aviation, their application remains insignificant. This results from the fact that such sheet metal shows poor plasticity and its cold-forming is almost impossible. Low drawability makes it impossible to obtain even such simple shapes as spherical cups. The authors of this study developed circular sheet-metal blanks with cutouts on their perimeter. The blanks allow for cold forming of spherical cups from Ti6Al4V titanium alloy sheet metal using conventional rigid tools. The cutouts proposed in the study affect plastic strain distribution, which in turn leads to an increase in forming depth by about 30%. The numerical analysis, performed using the PamStamp 2G System software based on finite element method, was verified experimentally.

Archives of Metallurgy and Materials, 2017

One of the important parameters of Refill Friction Stir Spot Welding is the so-called basic posit... more One of the important parameters of Refill Friction Stir Spot Welding is the so-called basic position of the tool. This is the arrangement of the pin and sleeve which occurs when the tool is plunged into the material. The basic positions can be divided into two categories. In the first category, the sleeve and the pin are above the sheet surface or below sheet surface and in the second category the pin is retracted within the sleeve or protrudes from it.The aim of the work was to test four settings of the basic position, and then determine the best setting of the basic position, without changing the other welding parameters. Joints made of an aluminum alloy 2024-T3 sheet having a thickness of 1.0 mm and an aluminum alloy D16UTW sheet having a thickness of 0.6 mm were analysed. The best setting of the basic position was determined based on assessment of the force carried in shear test, macrostructure and weld face of the joints.

Key Engineering Materials, 2016

The paper presents an analysis of load capacity for welded specimens made of titanium Grade 5 of ... more The paper presents an analysis of load capacity for welded specimens made of titanium Grade 5 of 0.8 mm thickness. The lap joins were made by Resistance Spot Welding (RSW). The load capacity for joints with a single spot were assessed. The joints were welded with 5 variants of welding parameters. On the basis of the capacity of the joints, the best performance were selected. The best welding parameters were used to make three types of joints with different spacing of the welds: with a single weld, the two welds arranged parallel to the shearing direction and two welds arranged perpendicular to the shearing direction. The load capacity, a plastic strains distribution and a method of cracking were assessed. An example of the feasibility of a beam construction made of titanium grade 5 sheets welded by resistance spot welding were shown.

Archives of Metallurgy and Materials, 2015

The dynamic development of the friction stir welding (FSW) technology is the basis for the design... more The dynamic development of the friction stir welding (FSW) technology is the basis for the design of durabe joints inter alia in the aviation industry. This technology has a prospective application, especially for the aluminum alloys. It is suitable for a broad spectrum of permanent joints. The joints obtained by FSW technology are characterized by good mechanical properties. In this paper, the friction stir spot welding joints were analysed. The example of a structure made using this technology were presented. The lap joints made of 2mm Al 6061-T6 sheets were the investigation subject. The different spot welds arrangements were analysed. The tensile test were performed with optical deformation measurement system, which allow to obtain the plastic deformation field on the sample surface. The plastic strain graphs for the characteristic line passing through the maximum deformation were registered and presented. The experimental results were compared to the FEM numerical analysis. The...

Archives of Metallurgy and Materials, 2015

FSW (Friction Stir Welding) and RFSSW (Refill Friction Stir Spot Welding) joints have been increa... more FSW (Friction Stir Welding) and RFSSW (Refill Friction Stir Spot Welding) joints have been increasingly used in industrial practice. They successfully replace fusion-welded, riveted or resistance-welded joints. In the last two decades, dynamic development of this method has stimulated investigations of the fast methods for joint diagnostics. These methods should be non-destructive and easy to be used in technological processes. The methods of assessment of joint quality are expected to detect discontinuities in the structures welded using FSW and FSSW methods. Reliable detection of flaws would substantially extend the range of applications of FSW joints across many sectors of industry, including aviation. The investigations carried out in this paper allowed for characterization of defects present in FSW and RFSSW joints. Causes of these defects were also stressed. An overview of the methodologies for assessment of joint quality was presented. Results of assessment of the quality of ...