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The precision of 3D printing in the fabrication of sintered dental metalwork is critical for successful clinical outcomes. However, during the initial trial of these metal components on the patient, a dimensional discrepancy often manifests itself, indicating a poor fit despite being modeled from precise intraoral scans. This necessitates additional corrections or reprinting, thus extending the duration of treatment, increasing costs, and raising concerns about the reliability of 3D printing and subsequent processing techniques. This study aims to quantitatively analyze the dimensional changes in sintered dental metalwork from the original intraoral scan to the final product and to evaluate whether these changes are influenced by the complexity of the metalwork design. Using a 3D scanner (Atos Core 200, GOM, Germany), the dimensions of the sintered metalwork were compared to the corresponding CAD models. Preliminary results indicate significant dimensional deviations, particularly in more complex designs, underscoring the need for improved accuracy in the 3D printing process to enhance clinical outcomes and efficiency.

The Optical methods can be highly useful for analysing Pipe Ring Tensile Specimens (PRTS) since they offer an accurate and non-destructive method of evaluation. Optical technologies have several uses, such as Digital Image Correlation method (DIC method), thermal imaging camera, and 3D scanning. The DIC method is used to measure stresses and full-field displacements. DIC analyses a speckle pattern that is applied to the surface of the specimen and can provide detailed information on strain distribution, deformation gradients, and likely failure spots. An infrared thermal imaging camera can be used to detect defects in pipe specimens, such as fractures or delamination, by tracking the distribution of surface temperatures. Temperature anomalies can indicate areas of intense stress or material degradation. A 3D scanner is a device that uses the shape, size, and texture of physical objects to digitise them into three-dimensional digital representations. The investigation focused on five distinct PLA PRTS. The study describes how to evaluate PLA PRTS using DIC method, thermal imaging camera, and a 3D scanner. The evolution of strain was monitored using the 3D Digital Image Correlation approach. Using a thermal imaging camera, the temperature field change in the PRTS was investigated during the test. In order to verify the cross-sectional shape of the PRTS after a fracture, 3D scanning was performed on each specimen.

Fracture mechanics, a fundamental field in materials science and engineering, deals with the study of crack initiation, propagation, and fracture resistance of materials. Traditional methods in fracture mechanics analysis often rely on analytical or numerical approaches, which may have limitations in capturing crack behavior under various loading conditions. To overcome these challenges, the 2D Digital Image Correlation (2D-DIC) method, a noncontact, full-field measurement technique, is employed to precisely quantify displacement and strain values. This paper investigates the application of the 2D-DIC method in the field of fracture mechanics. Through an experimental investigation that involves fracture toughness testing, crack growth monitoring, and fatigue crack propagation analyses, the effectiveness of 2D-DIC in capturing crack behavior is demonstrated. The results showcase the method's ability to accurately track crack propagation, providing valuable insight into crack growth mechanisms, and offering new data for understanding fracture mechanics phenomena. This paper contributes to advancing the field by highlighting the utility of 2D-DIC as a powerful tool for studying crack behavior and improving the overall understanding of fracture mechanics.

The three-point bending test is a valuable method for evaluating the mechanical properties of 3D-printed biomaterials, which can be used in various applications. The use of 3D printing in specimen preparation enables precise control over material composition and microstructure, facilitating the investigation of different printing parameters and advanced materials. The traditional approach to analyzing the mechanical properties of a material using a three-point bending test has the disadvantage that it provides only global information about the material’s behavior. This means that it does not provide detailed insight into the local strain distribution within the material. However, the 2D Digital Image Correlation (DIC) method offers additional insight, especially in terms of strain localization. DIC is an optical technique that measures full-field displacements and strains on the surface of a sample. PLA and enhanced PLA-X material were utilized to create three-point bending samples. The aim of this paper was to analyze and compare the influence of aging on the mechanical properties of PLA and enhanced PLA-X materials using three-point bending coupled with the DIC method. The results showed statistically significant differences between the PLA and PLA-X, for both the new and aged materials. The aged PLA samples had the highest average value of maximal force around 68 N, which was an increase of 8.8% compared to the new PLA samples. On the other hand, the aged PLA-X material had an increase of 7.7% in the average maximal force compared to the new PLA-X samples. When comparing the two materials, the PLA samples had higher maximal force values, 6.2% for the new samples, and 7.3% for the aged samples. The DIC results showed that both the new PLA and PLA-X samples endured higher strain values at Points 1 and 2 than the aged ones, except for the aged PLA-X sample at Point 2, where the new sample had higher strain values. However, for the first 5 min of the experiment, both

Conventional tensile testing is most commonly used for determining the basic mechanical properties of the material. However, this approach is challenging for in-depth analysis of material behaviour, especially related to heterogeneous materials. The Digital Image Correlation (DIC) method is a contactless optical method that overcomes the constraints of traditional experimental methods (e.g., strain gauge) and allows for full-field displacement and strain measurement. The paper specifically covers 2D-DIC application on tensile testing thin flat specimens prepared using cotton textile with 130 g/m2 density. Results show significant differences in von Mises strain values over the surface of the specimen, ranging from 8 to 24 %. The application of 2D-DIC in this case shows the significance of full-field analysis, as conventional usage of the tensile test would have missed the difference in mechanical properties of adjacent areas on the same specimen. 2D-DIC provides high spatial resolution, accuracy, real-time data acquisition, and visualization, making it a valuable tool for characterizing mechanical properties of thin flat specimens and understanding deformation mechanisms.

Different pipe manufacturing techniques, such as the manufacture of seamless pipes in the oil sector employing a conical shaft, necessitate data on the circumferential strain and stress condition of the pipe. The purpose of this study was to evaluating the displacement, strain, and stress behavior of a pipe ring tensile specimen (PRTS) in the hoop direction, as there was a lack of a standardized testing methodology. Five single S235JRH steel PRTS were tested for the study. The study describes how to test S235JRH steel PRTS with a Digital Image Correlation approach. The 3D Digital Image Correlation technique methodology was used to record the evolution of the strain. In the break zone and almost equivalent locations, all Single PRTS fractured. The experimental ultimate strength value's deviation value (also known as the real stress value) is greater than the theoretical ultimate strength value.

The three-point bending test is a widely used and important method for evaluating the mechanical properties of materials. Its versatility, applicability, and ability to provide valuable information on flexural strength, stiffness, and fracture toughness make it a valuable tool in materials science, engineering, and biomedical research. Digital Image Correlation (DIC) provides a high resolution and full-field measurement of deformation during the bending process. DIC also allows for the calculation of strain fields, which can be used to determine material properties such as Young's modulus and Poisson's ratio. This is particularly important in understanding the strain distribution and identifying potential failure mechanisms in the material. In this paper, the potential application of the 2D Digital Image Correlation method on three-point bending tests is presented.

In order to develop a non-standard method for determining the resistance to fracture and damage of pipeline materials, a new geometry of ring-shaped specimens with sharp notches or cracks has been defined. The need to develop a new method for testing of the specimens cut from the pipes arises due to the difficulties in determination of fracture mechanics parameters on thin-walled pressure pipelines, especially those with a smaller cross-section, by application of the standard procedures/specimens. Previous studies dealing with the topic of pipeline testing by non-standard methods are presented in the introductory part of the paper. In the experimental part of the research, tests on PRNT (Pipe Ring Notched Tension) and SENT (Single Edge Notched Tension) specimens are performed. Samples of these specimens were produced by SLS (Selective Laser Sintering) technique of additive production from PA12 (polyamide PA 2200) material. For the purpose of this study, a tool that is protected at the national level (in Serbia) as intellectual property is used for testing of the ring-shaped PRNT specimens. Tensile testing of both types of specimens is monitored by Aramis GOM 2M system; its operation is based on the method of digital image correlation, DIC. Additionally, finite element analyses are conducted on the PRNT and SENT geometries, enabling the calculation of the fracture mechanics parameter – Stress intensity factor K. It is concluded that the presented procedure based on the PRNT specimen has a good potential for use as a non-standard method for fracture resistance examination of pipeline materials. It can be performed on the specimens cut directly from the pipes (new or from exploitation). The dependence of the fracture resistance on the stress concentrator size is not pronounced, which means that the results depend dominantly on the material properties, rather than on geometry.

Fused deposition modeling is one of the most widely used 3-D printing technologies, among other additive manufacturing processes, because it is easy to use, can produce parts faster, and the cost of the finished part is low. Printing processes and finished parts are often studied and characterized using different techniques to collect mechanical, numerical, thermal and dimensional data, with the aim of improving and optimizing the result. The first part of this research is based on the observation of temperature changes with a thermal imaging camera during the fused deposition modeling printing process and during the cooling process after printing. Specimens of polylactic acid and polylactic acid-X improved with second-phase particles were prepared to compare the thermal and dimensional properties of the two materials. The obtained results determined the characteristic temperature behavior of the materials. In the second part of the research, a 3-D optical scanner was used to verify the stability and accuracy of the printed specimens over time. The proposed measurement period showed that stabilization of the parameters takes place, and further follow-up should be performed thereafter.

In this study, silicate nanofillers; dicalcium silicate, magnesium silicate, tricalcium silicate, and wollastonite; were synthesized using four different methods and incorporated into the epoxy resin to improve its mechanical properties. Characterization of the newly synthesized nanofillers was performed using Fourier-transformation infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The purpose of this study was to analyze newly developed composite materials reinforced with silicate nanoparticles utilizing tensile testing and a full-field non-contact 3D Digital Image Correlation (DIC) method. Analysis of deformation and displacement fields gives precise material behavior during testing. Testing results allowed a more reliable assessment of the structural integrity of epoxy composite materials reinforced using different silicate nanofillers. It was concluded that the addition of 3% of dicalcium silicate, magnesium silicate, tricalcium silicate, and wollastonite lead to the increasement of tensile strength up to 31.5%, 29.0%, 27.5%, and 23.5% in comparison with neat epoxy, respectively. In order to offer more trustworthy information about the viscoelastic behavior of neat epoxy and composites, a dynamic mechanical analysis (DMA) was also performed and rheological measurements of uncured epoxy matrix and epoxy suspensions were obtained.

Today, cosmetics have become an unavoidable feature of the modern way of life of individuals. The size of the global cosmetics market is estimated at 380.2 billion dollars in 2019 and is projected to reach 463.5 billion dollars by 2027, with a CAGR of 5.3% from 2021 to 2027. According to the client's request, a study of comparing three different cosmetic devices (ProLiftftr, MagicEye, MiniMeso) was conducted at the Centre for Optical Measurements of the Faculty of Mechanical Engineering, University of Belgrade. By using the images obtained with the PeakTech 5620 thermal imaging camera, the effects and quality of the device's effect on the skin were pointed out. All three devices have cosmetic performance and after a certain number of treatments show improvement in the form of skin tightening, wrinkle reduction, and reduction of swelling around the eyes, but one stands out in terms of application and treatment on the skin. To be specific, the device Proliftfrf has the best properties, which after moving the probe from the place of skin treatment allows faster cooling and a more pleasant treatment without burning and overheating. In addition, it can be seen that the Proliftfrf cosmetic device compared to the other two MiniMeso and MagicEyes has software that is easier to use and allows quick access, and clearly defined items, which increases the speed of work in salons, and allows more customers. This device achieves better treatment results in a shorter of therapy and thus increases the number of satisfied clients.

The aim of this paper is to determine the mechanical characteristics of parts obtained by Additive Manufacturing (AM). All specimens were printed on a Fuse 1 (FormLabs, Summerville, MA) 30 printer. This AM technology is SLS (Selective Laser Sintering). With this technology, objects of different shapes and dimensions can be produced at the same time. The only condition is that during printing, the parts must be at least 5 [mm] apart from each other. The thickness ofthe powder layer during printing was 110 microns. In this paper, one type of specimens are used to determine the mechanical characteristics, the dimensions of which were chosen according to specific standard. This standard is ISO 178 for 3-point bending specimens. The dimensions of the bending specimens are 96x8x4 [mm]. These specimens were produced in four batches, differing in printing orientation (horizontal and vertical) and printing location (printed on the edge and in the middle of the powder bed). The material used for printing the specimens is polyamide (PA 12). The flexural strength of this material is 66 MPa. After printing, specimens were tested on a standard tensile testing machine (SHIMADZU AGS-X 100kN). In the case of vertical bending specimens printed in the middle, the flexural strength after the test was 65.15 MPa, and for this type of specimens this is the smallest deviation from the value given in the literature. The greatest deviations of the flexural strength values are for vertical specimens printed on the edge, where the flexural strength is 58 MPa, and for horizontal specimens printed in the middle, the flexural strength is 81.7 MPa.

For various pipe manufacturing methods, data on the pipe's strain and stress state in the circumferential direction is necessary (e.g. in the oil industry, the process of manufacturing seamless pipes with a conical shaft). The purpose of this research is to create a method for determining the strain and stress behaviour of Pipe Ring Tensile Specimens (PRTS) in the hoop direction. The absence of official methods for assessing a PRTS suggests that it could be developed. The implementation of the digital image correlation approach for evaluating plastic PRTS is discussed in this research. A specially constructed steel instrument with two D blocks is used to test PRTS. Two D-shaped mandrels are fixed on the tensile tool and tensile testing equipment, and a 3D printed PRTS is placed over them. The three-dimensional Digital Image Correlation (3D DIC) approach was used to capture the strain evolution in the gage length of the specimens. All specimens are 3D scanned to evaluate the geometry of the PRTS cross-section following fracture. Six groups of PRTS were studied, with three different filling percentages (60, 90, and 100 percent) and two different geometric kinds (Single and Double PRTS). The results reveal that the kind and percentage of filling, as well as the printing method, affect material behaviour; however, the methodology using a DIC system, 3D printer, and scanner is an excellent tool for mapping entire strain fields in PRTS and thereby defining pipe mechanical properties.

Fused deposition modelling is, among the other additive manufacturing processes, one of the most frequently used three-dimensional printing technologies, because of its ease of use, high speed in production and low cost of the final part. Printing processes and finished parts are often examined and characterized using various techniques, for gathering the mechanical, numerical, thermal, dimensional data, with goal to improve and optimize the outcome. The first part of this research is based on the following the temperature changes using thermal imaging camera during fused deposi- tion modelling printing processes and during cooling process after printing is finished. Specimens were made from polylactic acid and polylactic acid - X improved with second-phase particles, in order to compare thermal and dimensional characteristics of both materials. Obtained results determined characteristic temperature behavior of materials. The second part of research employed optical 3D scanner for verification the stability and accuracy of printed specimens over time. Proposed period of measuring has shown that stabilization of parameters is taking place, and further follow-up should be done afterwards.

This work presents the fabrication and tensile testing of polyamide specimens fabricated by selective laser sintering (SLS). Two geometries are considered: SENT (Single Edge Notched Tension) and PRNT (Pipe Ring Notched Tension) specimens. Experimental testing of these specimens is a step in development of a new method for testing of properties of the pipeline materials. The samples were produced by SLS (Selective Laser Sintering) additive production technique. The samples were made from polyamide PA12 on EOS Formiga P100 machine (fabrication parameters: laser power 30 W, print layer height 0.1 mm, scanning speed 1.6-5 m/s, operating temperature 170⁰C). Testing was performed in the displacement control on a universal tensile testing machine Shimadzu AGS - X. On this machine, the values of force as well as the values of stress and strain were obtained directly from the Trapezium X software. Special attention in this work is devoted to two important aspects: fixing of the ring specimen for testing and influence of friction between the specimen and the tool. The results obtained on the examined specimens indicate that this study is a valuable contribution for further development and verification of the new fracture resistance testing procedure for different pipeline materials.

Contact lenses have been used and manufactured for decades now, but recently 3D printing technologies were introduced as a new way of production. As a rapidly developing technology, 3D printing offers new possibilities for development and advantages in the manufacturing process of lenses, due to easy customization and geometry modelling. Standard production is not leaving much space for individual demands, concerning different ophthalmic diagnoses and unique patients’ eye characteristics. In this paper, the main emphasis is on the further development of the design and characteristics of lenses fabricated by this technology that can satisfactorily overcome the drawbacks of production approaches used until now. Areas of possible improvements are significant, meeting the individual demands of patients, customizing needed parameters for better therapy, biocompatibility, the possibility to integrate different optical sensors for diagnostics, even making the smart lenses, etc. There are a very limited number of studies dealing with 3D printing and examination of printed contact lenses, which leads to the conclusion that this is the research area of the future.

Data on the strain and stress status of the pipe in the circumferential direction are required for various pipe manufacturing procedures (e.g., in the oil business, the process of manufacturing seamless pipes with a conical shaft). The aim of this study is to develop a procedure to determine the strain and stress behavior of Pipe Ring Tensile Specimens (PRTSs) in the hoop direction, as there are a lack of official standardized methods for testing PRTS. This paper discusses the application of the Digital Image Correlation method for testing plastic PRTSs. PRTSs are tested using a specially designed steel tool with two D blocks. A 3D-printed PRTS is placed over two D-shaped mandrels, which are fixed on a tensile tool and tensile testing machine. The strain evolution in the gage length of the specimens is captured using the three-dimensional Digital Image Correlation (3D DIC) method. To check the geometry of the cross-section of the PRTS after fracture, all the specimens are 3D scanned. For the study, six groups of PRTS are analyzed, consisting of three filling percentages (60, 90, and 100%) and two geometry types (Single and Double PRTS). The results show that the type and percentage of filling, as well as the method of printing, affect the material behavior. However, the approach with the DIC system, 3D printer, and scanner shows that they are effective instruments for mapping complete strain fields in PRTS, and thus are effective in characterizing the mechanical properties of pipes.

Due to its remarkable qualities, carbon fiber epoxy composite sandwich panels are used in a variety of engineering applications. The goal of this research is to use tensile testing and a full-field non-contact 3D Digital Image Correlation (DIC) method to characterize carbon fiber reinforced composite sandwich panels with varied fiber orientations (0°/90° and ± 45°). The tested materials were composed of carbon fiber prepregs with epoxy resin systems and Aramid synthetic fiber. The properties of the materials were determined using full-field data derived from 3D DIC measurements and a set of experiments by according to ASTM standards. Values of maximum stress and strain at entire areas, break stress and strain, and toughness at entire areas and, modulus of elasticity of both structures were compared. The adherend's full-field, out-of-plane deformation, strain distribution, and strain evolution along the bond line were captured using a digital image correlation method, allowing the fracture mechanism to be visually defined. Since DIC produces the displacement field, the strain field must be deduced from it. The orientation of the fibers had a significant impact on the tensile properties of the tested materials. The results revealed that the specimen with 0°/90° fiber orientation had higher break stress and brittle fracture, whereas the specimen with ± 45° fiber orientation twisted in the fiber direction had higher elongation values while carrying the applied load. In order to complement previously obtained results, scanning electron microscopy (SEM) analysis of the fibers and core, as well as fracture surfaces was performed.

Procedura ispitivanja epruveta oblika prstena dobijenih iz cevi nije standardizovana i potpuno definisana. Cilj ove studije je razvijanje procedure za određivanje polja pomeranja i deformacija kod epruveta oblika prstena. Predložena je geometrija epruvete sa jednostrukom konfiguracijom standardne epruvete. Za potrebe ove studije, epruvete se proizvode tehnologijom 3D štampe sa standardnim polilaktičnim polimerom (PLA). Jedan od glavnih elemenata eksperimentalne postavke za ispitivanje epruveta oblika prstena je specijalno razvijeni alat sa dva D bloka. Alat se postavlja na kidalicu i prenosi opterećenje na unutrašnju površinu uzorka simulirajući unutrašnji pritisak. Metoda korelacije digitalnih slika koristi se za analizu polja pomeranja i deformacija na spoljašnjoj površini uzorka. Eksperimenti se izvode pri brzinama od 1 mm/min na kidalici Shimadzu AGS-X. Rezultati ispitivanja pokazuju da su kod predloženih epruveta lomovi nastali u zonama snimanja, tj. u definisanim suženjima i ukazuju na mogućnost daljeg poboljšanja postupka ispitivanja i geometrije epruveta.

Poslednjih godina, razvoj 3D štampe je veoma značajan u domenu različitih proizvodnih tehnologija i industrije. Proizvodnja delova na ovaj način je vrlo fleksibilna, jer je na jednom uređaju moguće napraviti više različitih modela, različite geometrije. Da bi proces 3D štampanja bio izveden na najprecizniji način, potrebno je pažljivo izabrati parametre štampe. U ovom radu prikazano je istraživanje promena temperaturnih polja korišćenjem termovizijske kamere nakon procesa 3D štampe polilaktičnog polimera (PLA), tehnologijom modelovanja istopljenog filamenta (FDM). Cilj rada je utvrđivanje i analiza promena temperatura koje se dešavaju u toku hlađenja uzorka nakon procesa 3D štampe i uticaja na promenu geometrije epruvete.

U ovom radu biće prikazan razvoj dizajna epruveta oblika prstena sa dve prsline kao i optimizacija parametara izrade. Epruvete su izrađene tehnikama aditivne proizvodnje tipa SLA (Stereolitography Apparatus) i FDM ( Fused Deposition Modeling). Odabrane tehnike omogućuju veoma brz razvoj i izradu epruveta oblika prstena za zatezanje - PRNT (Pipe Ring Notched Tension). Epruvete izrađene navedenim tehnikama su ispitivane u okviru razvoja metode za ispitivanje PRNT epruveta i određivanja parametara mehanike loma kod uzoraka izrađenih od PLA premium filamenta firme German RepRap i fotopolimernog materijala tipa Photopolymer resin Gray ( FLGPGR04) firme FormLabs. Cilj ovog rada je optimizacija parametara 3D štampe u cilju dobijanja specijalno oblikovanih epruveta oblika prstena sa dve prsline za ispitivanje zatezanjem u obimnom pravcu. Ponovljivost procesa, mogućnost praćenja parametara mehanike loma: otvaranje usta prsline CMOD (Crack Mouth Opening Displacement), otvaranje vrha prsline CTOD (Crack Tip Opening Displacement) a kasnije i numerički proračun vrednosti J integrala, omogućila je izrada epruveta ovim tehnikama.

Digital Image Correlation (DIC) is applied to evaluate stress-strain diagrams for welded joints in two different ways. The first one is based on the measures strains along the welded joint, including all 3 zones of interest, base metal (BM), weld metal (WM), and heat-affected-zone (HAZ) subdivided into fine grain (FG) and coarse grain (CG) subzones. Specially designed iterative procedure has been used to determine coefficient of Holomon law to get true stress-strain curves for welded joint made of HSLA steel Niomol 490. The second one presents new methodology for evaluating true stress-strain diagram, based on measured values of contraction, as obtained by 3D DIC, rather than more conventional analytical formulas. New methodology is applied to undermatched welded joint, made of martensitic steels X10 CrMoVNb 9-1.

Modern home windows include new approaches in their design and new material utilization to achieve best resistance to harsh weather conditions and to achieve best possible thermal insulation. Chosen internal structure of window frame and selected material affect on structural life. Integrity assessment of home window frames covers experimental and numerical approaches, including experimental DIC method (Digital Image Correlation-DIC) and FEA (Finite Element Analysis) numerical method. The aim of this research is to find the matching between both techniques and to use only numerical method in future to assess the structural life of home window frames with different internal structures in the design and different materials. Experimental testing is performed on the Universal tensile testing machine ‘’Shimadzu AGS-X’’ with 100kN load capacity, which is sufficient for home window frame testing. DIC cameras are used for recording of the experimental technique and the output are displacements and deformations on observed structure. FEA simulation accepts the before experimental conditions, i.e. maximal load, material characteristics and geometry. Matching of experimental results and attained FEA simulation will allow for easier Integrity assessment using only numerical simulations for future tests. Therefore, with mentioned technique new internal structures of windows and different materials can be simulated and the obtained results will show if the chosen home window frame structure and material selection is sufficient enough for practical use.

Pipe material propertise test is very important for quality investigate of pipe construction. Many studies that have been conducted are based on use ring shape specimens. Previous research has used weaker pipe materials and larger diameters, which facilitates tool making. This state of the art has led to the development of a new approach to testing pipe rings of larger thicknesses and smaller diameters (e = 6.32mm, DN32) as well as defining a better test procedure. Using DIC cameras (Digital Image Corelation), stress state analysis was performed and deformations on the outer surface and side of the ring (pipe wall) were analyzed. The outer surface of the ring and the thinning of the test tube in the axial direction as well as the elongation of the measuring part of the test tube were recorded with two cameras. With the third camera, the lateral side of the specimen was recorded so that the change in the thickness of the ring as well as the occurrence of bending in the radial plane during the test were analyzed. The test results are based on data on deformation, thickness reduction in the axial and radial directions. The test results enable the assessment of the condition of the pipe material and the assessment of its service life. The use of ring-shaped test tubes facilitates production and provides better results compared to the flattening method.

Structural Health Monitoring (SHM) technologies are an important part of the system for detection and characterization of any type of damages of engineering structures. Various technologies have been applied in different engineering sectors in last several decades – strain gauges, acoustic emission, fibre optic sensors, etc. One of the methods that has a high potential for application in sector of pressure vessels, especially on complex geometrical parts, is 3D Digital Image Correlation (3D-DIC) method. 3D-DIC method enables full-field displacement and strain measurement. The aim of this paper was to investigate the possibilities of application of the Aramis system (GOM, Germany) based on 3D-DIC method on several cases typical for pressure vessels and its influence on structural health – crack detection and crack propagation monitoring and stress concentration areas of complex structures in the vessel-nozzle joint (sphere to cylinder and cylinder to cylinder connections). Aramis software was used to measuring von Mises strain fields and displacements. The results showed that 3D-DIC method is suitable for structural health monitoring of pressure vessels during their lifespan.

One of the current problems in practice of preparing functional parts, prototypes and constructions is insufficient knowledge of 30 printing parameters for various advanced materials, which often results in failure to obtain required 30 prints. Users of 30 printers and distributors alike are at high risk that the results of their 30 printing may fail due to the use of advanced materials that are not sufficiently tested. Chosen 30 printing technology is FDM (Fused Deposition Modeling), a commercially available and widespread additive manufacturing technology. Crucial impact on mechanical properties and durability of 3D printed FDM parts are chosen parameters for printing. The input of parameters is done using adequate slicer software, which prepares the G-eode for stepper motors and heaters-who runs the whole 30 printing process on the machine. Previous studies show that printing parameters such as layer height, print speed, infi/1 pattern and percentage, print orientation and temperature have a crucial impact on mechanical properties of printed parts. This technology still shows improvements, mostly in the field of new materials. Every breakthrough in the material field requires thorough testing, in order to acquire mechanical properties and determine material behaviour in exploitation. In order to extend the application of production of functional parts and prototypes obtained using additive manufacturing technologies, overviewing exploitation behaviour of conventional and advanced materials due to different conditions of 30 printing, the 30 printing parameters have been varied in order to attain its influence on mechanical properties of experimental samples, that are to be used in tensile testing. This research shows that prime mechanical properties, such as tensile strength, deformation at break, Young's modulus and toughness, may vary up to 30% in their value according to chosen printing parameters.

Examination of strain field underneath the teeth and bone structure of mandible for "in vitro" conditions requires thorough preparation of the examinee and equipment. For the purpose of examination of different regions of partly-edentulous mandible, the design solutions for examination of strain fields located on the determined points have been shown for different types of compensations. Strain measurement was performed using contactless optical 3D system ARAMIS 2.0. Mandible model with several remaining teeth was additively manufactured using SLA technology. The measurement of acting force was performed using a dynamometer, with the maximum applied force intensity of BOON. The results of this study showed that developed experimental setup enables comparison of influence of different teeth geometries and metal compensation designs to the selected areas of artificial partly-edentulous mandible resulting in specific strain distribution.

Heat losses in buildings have high influence on construction materials choice, size and quality of windows, doors or glass roofs and the construction processes. For a 10 floor-building, heat losses through windows are almost half of the losses of the whole building. With that in mind, improving the thermal protection of windows and other glass surfaces can increase energy savings. One example for thermal protection increase is using blinds on windows. Influence of the size and position of the windows blinds on heat losses is analysed in this paper. A mathematical model was developed and experimental study was conducted to obtain the values of thermal losses in the function of the position and size of the blind openings. The obtained results showed the ratio of the amount of heat for the window with and without a blind. According to the measured values, the thermal insulation is increased for about 18 % on the window with blinds. The use of the blinds is profitable and the mentioned savings can contribute to the lower energy consumption in house heating and cooling.

The tool is used to test the radial tensile characteristics of the pipeline material from which the specimen are made. The tool enables testing of steel ring specimen used in various industries (eg thermal power plants).

Examination of strain field underneath the teeth created due to influence of bite force in "in vitro" conditions requires thorough preparation of the examinee and equipment. Failure of tooth-compensation bond is often caused as a consequence of inadequate processed tooth design causing uneven strain distribution. In this paper design solutions for examination of strain field located underneath the teeth have been shown for different types of teeth and compensations. Strain measurement was performed using con1Bctless optical 3D system ARAMIS 2.0. Mandible model with teeth was additively manufactured using SLA technology. Cap shape compensations are made of silver. Measurement of force was performed on a dynamometer, with a maximal capacity of 800N. Obtained results show how developed experimental setup enables comparison of influence of different shapes of teeth and compensations on strain distribution.

The problem of loads caused by the temperature dilatations in pipes and its effect on strain and stress state of the entire pipeline is common problem in engineering practice. This paper describes three methods for calculation of loads that can occur in the pipeline caused by temperature differences. The study presented in the paper analysed the L shaped pipeline configuration with an operating temperature at 200°C, pipeline material P235GH, angle between legs of the L shaped pipeline is 90, pipe dimension DN 300 and operating pressure is 10 bar (absolute pressure). The calculation was presented according to standards EN 13480-3 and AD 2000 and Russian method commonly used in engineering practice. The three methods have different engineering approaches for solving the same type of the problem, so the specific differences were presented in the paper. All the results are presented in unified tables for easier comparison and analysis. It can be conducted that all three presented methods showed similar results and choosing the most suitable one for the practical application is mainly determined by the type of the result needed for the specific application.