Search Results (101)

The paper investigates experimentally the influence of infill density, infill pattern, layer height, wall number, printing orientation, and material color on the impact strength of 3D-printed PLA (polylactic acid) samples by using the Charpy test method. The used printing method is FDM (Fused Deposition Modeling) performed on a desktop printer. For each parameter changed in the study, five separate unnotched specimens were produced and tested, and the average impact strength value was taken into account. The filament rolls went through a drying process before printing and were then stored in a low-humidity environment filled with desiccant in order to minimize the effect of absorbed humidity in the filament during the experiments. The conditioning and testing of samples were performed according to the EN ISO 179-1 standard. Dimensional accuracy, print times, and filament consumption were also estimated in the study. The results revealed that the infill density, infill pattern, and wall number have a larger influence on the impact energy absorbed by the samples in comparison to the layer height, printing orientation, and the PLA filament color. The best optimization of the studied mechanical property was obtained by increasing the infill percentage and the number of walls. Applying different PLA colors has a slight effect on the impact strength, yet it should be taken into consideration when designing 3D-printed products that are intended to withstand impact. Moreover, it was found out that the studied parameters have an insignificant effect on the dimensional accuracy of the produced samples. Full article

Fused Filament Fabrication (FFF) is an additive manufacturing technique that constructs parts by extruding material layer by layer. It offers advantages such as rapid prototyping, cost-effectiveness, and the ability to produce complex geometries. This study investigates the mechanical behavior of a composite filament composed of silicon carbide (SiC) ceramic particulates embedded in a polylactic acid (PLA) matrix, fabricated via FFF. Pure PLA specimens were also printed and tested to serve as a baseline. A Design of Experiments (DOE) methodology was employed to evaluate the influence of key printing parameters on mechanical properties, including Young’s modulus, yield strength, and ultimate strength. Microstructural analysis was performed on printed specimens using scanning electron microscopy (SEM). For compression testing, the parameters studied were infill percentage, number of shells, and print orientation. For tensile testing, the parameters included layer height, number of shells, and infill angle. Results indicated that infill percentage had the most significant impact on compressive properties, while layer height was the dominant factor in tensile performance. These findings provide insights into optimizing FFF process parameters for ceramic-particulate-reinforced polymer composites. Full article

Fused deposition modelling (FDM) has become a cost-efficient and highly effective technique in 3D printing. Polyethylene terephthalate glycol (PETG) is a prevalent thermoplastic biofilament, and it exhibits resistance to water, heat, and chemicals. It is often regarded as waterproof and possesses exceptional thermal resistance. This study aimed to improve the mechanical properties of PETG by employing a 50% infill density along with certain infill patterns and raster angles for the top, bottom, and interstitial layers. Initially, Response Surface Methodology (RSM) was used to create the regression model by using various parameters; then, it was used to examine the experimental data and find the factors that have a significant impact on mechanical properties. The structural load-carrying behaviour of the specimen was analysed using a Scanning Electron Microscope (SEM). The tensile results showed that the maximum tensile strength attained was 43.09 MPa and the modulus value was 1.18 GPa and the yield strength was 21.01 MPa. The compressive properties showed that the highest strength was 25.90 MPa, and a modulus of 2.87 GPa was attained. The combination of a rectilinear and concentric infill pattern obtained more strength than the other combinations, and the raster angle acted as the most crucial factor on the strength of the specimen. A determination (R²) value over 90% signified strong suitability, while the error percentage between estimated and experimental data remained below 5%, showing that the regression values were satisfactory. Full article

A cantilever beam is a mechanical structure fixed at one end and free at the other. It converts the applied external forces into bending and shear force; therefore, it should be designed to resist deflection. The fundamental natural frequency of the cantilever beam depends on its material properties, geometry, and supporting conditions. This work studied the effect of adding an accelerometer and a motor, which represent multiple masses, on the fundamental natural frequency of a cantilever beam. The beam is also supported by a 3D-printed spring at its free end. Three-dimensional-printed springs with different infill percentages (20%, 50%, 80%, and 100%) were used with different infill patterns (concentric, grid, and triangle) to study the effect of these parameters on natural frequency. The results showed that the triangle pattern gives the best results for fundamental natural frequency and resulting force values. In addition to that, the triangle pattern with 80% infill percentage is preferred for printing as compared with 100% infill percentage because it gives better vibration results. Full article

This study investigates post-processing treatments aimed at enhancing the mechanical properties of Polyether Ether Ketone (PEEK) parts fabricated via Fused Filament Fabrication (FFF). FFF-printed PEEK components often exhibit anisotropy and weak interlayer adhesion, which limit their structural performance. To address these issues, a resin infiltration treatment is proposed that yields improvements in flexural strength and strength-to-weight ratio across specimens with different infill percentages. The effectiveness of resin infiltration is compared to that of a thermal post-processing treatment. Experimental results indicate that, although thermal treatment enhances crystallinity, it does not substantially improve interlayer bonding or mitigate anisotropy. In contrast, resin infiltration significantly enhances flexural strength, particularly in specimens with lower infill percentages, by effectively filling pores and reinforcing interlayer adhesion. Overall, the findings demonstrate that vacuum-assisted thermosetting resin infiltration is a promising post-processing technique for improving the mechanical performance of 3D-printed PEEK, achieving a mean flexural strength of up to 34 MPa, approximately 80% higher than that of untreated specimens with 100% infill. Additionally, a cost analysis comparing both post-processing methods is presented, highlighting the cost-effectiveness of resin infiltration as a viable solution to overcome the inherent limitations of FFF-printed PEEK. Full article

Optimizing printing parameters is crucial for enhancing the efficiency, surface quality, and dimensional accuracy of Fused Deposition Modeling (FDM) processes. A review of numerous publications reveals that most scholars analyze factors such as nozzle diameter and printing speed, while few investigate the impact of layer thickness, infill density, and shell layer count on print quality. Therefore, this study employed 3D slicing software to process the three-dimensional model and design printing process parameters. It systematically investigated the effects of layer thickness, infill density, and number of shells on printing time and geometric accuracy, quantifying the evaluation through volumetric error. Using an ABS connecting rod model, optimal parameters were determined within the defined range through orthogonal experimental design and signal-to-noise ratio (S/N) analysis. Subsequently, a backpropagation (BP) neural network was constructed to establish a predictive model for process optimization. Results indicate that parameter selection significantly impacts print duration and surface quality. Validation confirmed that the combination of 0.1 mm layer thickness, 40% infill density, and 5-layer shell configuration achieves the highest dimensional accuracy (minimum volumetric error and S/N value). Under this configuration, the volumetric error rate was 3.062%, with an S/N value of −9.719. Compared to other parameter combinations, this setup significantly reduced volumetric error, enhanced surface texture, and improved overall print precision. Statistical analysis indicates that the BP neural network model achieves a Mean Absolute Percentage Error (MAPE) of no more than 5.41% for volume error rate prediction and a MAPE of 5.58% for signal-to-noise ratio prediction. This validates the model’s high-precision predictive capability, with the established prediction model providing effective data support for FDM parameter optimization. Full article

Open Ground-Storey (OGS) buildings, widely adopted for functional openness, are highly vulnerable to seismic collapse due to stiffness irregularity at the ground storey (GS). The magnification factor (MF), defined as the amplification applied to GS column design forces, acts as a practical strengthening measure to enhance GS stiffness and thereby mitigate the soft storey failure mechanism. While earlier studies recommended fixed MF values, their lack of adaptability often left stiffness deficiencies unresolved. This study develops a rational framework to quantify and predict the required MF for OGS columns, enabling safe yet functionally efficient design. A comprehensive set of three-dimensional reinforced concrete OGS models was analyzed under seismic loads, covering variations in plan geometry, ground-to-upper-storey height ratio (Hr), and GS infill percentage. Iterative stiffness-based evaluations established the MF demand needed to overcome stiffness deficiencies. To streamline prediction, advanced machine learning (ML) models were applied. Among these, black-box models achieved high predictive accuracy, but Symbolic Regression (SR) offered an interpretable closed-form equation that balances accuracy with transparency, making it suitable for design practice. A sensitivity analysis confirmed the Hr as the most influential parameter, with additional contributions from other variables. Validation on additional OGS configurations confirmed the reliability of the SR model, while seismic response comparisons showed that Modified OGS (MOGS) frames with the proposed MF achieved improved stiffness, reduced lateral displacements, uniform drift distribution, and shorter fundamental periods. The study highlights the novelty of integrating interpretable ML into structural design, providing a codifiable and practical tool for resilient OGS construction. Full article

Hip implant optimization is increasingly receiving attention due to the development of manufacturing technology and artificial intelligence interaction in the current research. This study investigates the development of hip implant stem design with the application of lattice structures, and the utilization of the MATLAB regression learner app in finding the best predictive regression model to calculate the mechanical behavior of the implant’s stem based on some of the design parameters. Many cases of latticed hip implants (using 3D lattice infill type) were designed in the ANSYS software, and then 3D printed to undergo simulations and lab experiments. A surrogate model of the implant was used in the finite element analysis (FEA) instead of the geometrically latticed model to save computation time. The model was then generalized and used to calculate the mechanical behavior of new variables of hip implant stem and a database was generated for surgeon so they can choose the lattice parameters for desirable mechanical behavior. This study shows that neural networks algorithms showed the highest accuracy with predicting the mechanical behavior reaching a percentage above 90%. Patients’ weight and shell thickness were proven to be the most affecting factors on the implant’s mechanical behavior. Full article

This study investigates the influence of key fused deposition modeling (FDM) process parameters, namely, print speed, infill percentage, layer thickness, and layer width, on the tensile properties of PLA specimens produced using 3D printing technology. A Taguchi L9 orthogonal array was employed to design the experiments efficiently, enabling the systematic evaluation of parameter effects with fewer tests. Tensile strength and elongation at break were measured for each parameter combination, and statistical analyses, including the signal-to-noise (S/N) ratio and analysis of variance (ANOVA), were conducted to identify the most significant factors. The results showed that infill percentage significantly affected tensile strength, while layer thickness was the dominant factor influencing elongation. The highest tensile strength (47.84 MPa) was achieved with the parameter combination of 600 mm/s print speed, 100% infill percentage, 0.4 mm layer thickness, and 0.4 mm layer width. A linear regression model was developed to predict tensile strength with an R² value of 83.14%, and probability plots confirmed the normal distribution of the experimental data. This study provides practical insights into optimizing FDM process parameters to enhance the mechanical performance of PLA components, supporting their use in structural and functional applications. Full article

Batteries are used as energy storage devices in various equipment. Today, research is focused on solid-state batteries (SSBs), replacing the liquid electrolyte with a solid separator. The solid separators provide electrolyte stability, no leakage, and provide mechanical strength to the battery. Separators are mostly manufactured by either traditional processes or 3D printing technologies. These processes involve making a slurry of plastic, active and conductive material and usually adding a plasticizer when making thin films or filaments for 3D printing. This study investigates the additive manufacturing of solid-state electrolytes (SSEs) by employing fused deposition modeling (FDM) with recyclable, bio-derived polylactic acid (PLA) filaments. Precise control of macro-porosity is achieved by systematically varying key process parameters, including raster orientation, infill percentage, and interlayer adhesion conditions, thereby enabling the formation of tunable, interconnected pore networks within the polymer matrix. Following 3D printing, these engineered porous frameworks are infiltrated with lithium hexafluorophosphate (LiPF₆), which functions as the active ionic conductor. A tailored thermal sintering protocol is then applied to promote solid-phase fusion of the embedded salt throughout the macro-porous PLA scaffold, resulting in a mechanically robust and ionically conductive composite separator. The electrochemical ionic conductivity and structural integrity of the sintered SSEs are characterized through electrochemical impedance spectroscopy (EIS) and standardized mechanical testing to assess their suitability for integration into advanced solid-state battery architectures. The solid-state separator achieved an average ionic conductivity of 2.529 × 10⁻⁵ S·cm⁻¹. The integrated FDM-sintering process enhances ion exchange at the electrode–electrolyte interface, minimizes material waste, and supports cost-efficient, fully recyclable component fabrication. Full article

This study aims to evaluate the feasibility of using Fused Deposition Modeling (FDM)/Fused Filament Fabrication (FFF) 3D printing for the emergency replacement of damaged components in the marine industry, focusing on mechanical properties, dynamic stiffness, and manufacturing efficiency. The authors’ research interests include the application of incremental and hybrid methods for the production of new, fully functional parts that constitute equipment for ships and yachts. The methods described in this paper can also be used to produce replacement parts in emergency conditions when there is a need for a temporary replacement of a damaged component. When testing parts made with 3D printing technology, the authors used modal analysis methods to estimate the dynamic stiffness of bracket support samples. The dynamic analysis of the tested parts was conducted using both the cavity method and the incremental method with FDM and FFF 3D printing. This study focused on determining their resonance curves. Based on these curves, the dynamic stiffness of the samples was calculated. Understanding the changes in dynamic stiffness of 3D printed parts depending on their degree of filling is one of the critical parameters from the point of view of the possibility of the safe operation of parts manufactured with this method. The results show that the dynamic stiffness of 3D printed parts depends significantly on the infill percentage. This article also presents the results of a simplified technical and economic analysis of the bracket support manufacturing samples produced by machining, incremental, and hybrid methods. The quality parameters of the geometric structure of the parts made with the manufacturing methods analyzed in this paper are also compared with each other. Full article

Poly (lactic acid) (PLA), a biodegradable polymer, is widely used in medical applications, particularly for 3D-printed tissue engineering scaffolds. The fused filament fabrication (FFF) 3D printer is an available processing tool for PLA. The nozzle scan pattern and interior fill percentage (IFP) considerably influence the mechanical properties of formed structures and may have dominant effects on the rates at which the mechanical properties of PLA deteriorate. When the IFP is set to a low value, such as 80%, internal gaps form within the structure, leading to different deterioration patterns compared to structures formed under the IFP 100% condition. In this study, we fabricated test pieces with an FFF 3D printer using three different nozzle scan patterns. After immersing the test pieces in phosphate buffer saline (PBS) for up to 120 days, the water content was measured and the test pieces underwent tensile testing to determine the tensile strength, elastic modulus, and breaking energy. Both the deterioration rate and water uptake rate varied among the different nozzle scan patterns used for the fabrication. For the test pieces formed with internal gaps, the water uptake and deterioration proceeded in two stages. The deterioration rate of the structures with internal gaps was faster than that of the fully filled structures. The data obtained in this study will be useful for the design of PLA structures applied in tissue engineering. Full article

This study investigates the influence of various printing parameters on the tensile, compressive, and bending stiffness of fused deposition modeling (FDM)-printed polylactic acid (PLA) parts through a comprehensive full factorial design of experiment. Key factors, including infill percentage, infill pattern, number of outer shells, and part orientation, were systematically varied to quantify their impact on mechanical performance. A total of 36 parameter combinations, selected based on a literature review and experimental feasibility, were tested using standardized specimens: beams for bending, cylinders for compression, and dogbones for tensile testing. Mechanical tests were performed according to ISO 5893:2019, employing a 1 kN load cell to determine stiffness and elastic modulus. The results indicate that the number of outer shells and infill density are the most influential parameters, whereas infill pattern and part orientation have a minor effect, depending on the loading condition. This study provides a novel and robust evaluation of the interactions between key printing parameters, offering new insights into optimizing the mechanical properties of FDM-printed parts. These findings establish a foundation for further optimization and material selection in future additive manufacturing research. Full article

The study of biomimetics allows for the creation of various structures inspired by nature. This work investigates the impact of using a bio-inspired tool path for manufacturing porous plates via 3D printing. The Bouligand (or plywood-like) structure is prevalent in several biological components. Structures that mimicked the Bouligand design concerning the tool path were printed and compared to uniform plates produced with a rectilinear pattern through mechanical testing. Quasi-static and dynamic tests were conducted on specimens with infill densities ranging from 25% to 100%. Results indicated that the Bouligand pattern displayed superior specific energy absorption at 75% infill density. This bio-inspired path pattern also provided excellent elongation during quasi-static and dynamic failure—the fracture pattern of the bio-inspired path adhered to the Bouligand structure. In contrast, brittle failure was demonstrated by the specimen with a rectilinear pattern at varying infill percentages, while the bio-inspired pattern enhanced the toughness of the polymer specimens. Full article

In this article, the authors present the results obtained within a complex experimental program that focuses on determining the tribological characteristics of the friction materials used in transmission belts, which are critical active components in manipulators within the pharmaceutical industry. The elements of transmission belts, having the role of ensuring the movement of cardboard packaging—used when packing the foils with medicine capsules—and stopping them during the insertion of the foils, were studied. This repetitive cycle—travel-braking—leads to the wearing of the friction material on the active surface of the belt. The experiments were carried out in a dry environment (air) by testing different types of friction materials (original belt, 3D printed TPU 60A, and TPU 95A). While the study is limited to these three materials, the results highlight the significant influence of material type and infill percentage on the coefficient of friction (COF) and wear resistance. TPU 60A achieved the highest COF at 100% infill, indicating a superior grip but experienced substantial wear, under the same conditions. Conversely, TPU 95A demonstrated a lower COF, suggesting reduced grip, but exhibited exceptional wear resistance. The aim of the research is to provide a preliminary investigation into the materials’ wear resistance and braking effectiveness. The experiments utilized appropriate samples to replicate real operational conditions, particularly focusing on the nature of contact between the moving belt and the packaging. Full article