CAD Model Research Articles

Numerical analysis and evaluation of a semi-heavy guardrail system

The continuous increase in traffic accidents, following the rise in the number of vehicles in traffic and their speed, requires the development of research on the design of active and passive safety systems. This research mainly aims to compare the performance of commonly used passive safety systems (semi-heavy W-beam guardrails) mounted on roadside and pedestrian bridges to protect vehicles and pedestrians. It is intended to reduce the deformations of the vehicle upon impact with the protective device mounted between the roadside and the pedestrian area for the protection of the vehicle occupants; reduce the parapet working width for the pedestrian’s safety; and maintain the vehicle’s trajectory from the moment of impact to the final movement, between the guardrail and the median axis of the road, to ensure the protection of other road users. A CAD model of the vehicle-guardrail scenario was developed to achieve these objectives. Load simulation cases are performed using the finite element method according to the European standards SR EN 1317 for impact tests of vehicles - TB 42, recommended for semi-heavy guardrails.

Direct additive manufacturing of transparent fused silica glasses using an integrated paste printing and laser in-situ melting technology

Fused silica glasses are of great importance for applications in optics, photonics, electronics, and biochemistry. However, their harsh processing nature still constrains the design and development of fused silica glasses for advanced applications. Additive manufacturing (AM) is among the promising techniques to improve the fabrication of fused silica glasses. Herein, we develop an integrated paste printing and laser in-situ melting technology to additively manufacture fused silica glasses without post-heat-treatments. For every layer, the fused silica paste was first printed by an air-pumped dispenser based on the predesignated CAD model, and subsequently melted by a CO2 laser to become transparent glasses. To improve the paste printing process, the shear thinning property of the developed fused silica paste was investigated to evaluate the printability of the paste, and the control strategy of the paste printing parameters was developed for precise thickness control of the printed paste layer. By optimizing the laser processing parameters, the surface waviness and roughness of the laser-melted glass layers were effectively minimized, indicating the surface uniformity was improved. To evaluate the optical properties of the laser-melted glasses, the optical transmittance and refractive indices of the fused silica glasses melted by different laser powers were characterized. Through stacking the laser-melted fused silica glasses layer-by-layer, three-dimensional (3D) fused silica glass components with unusual thin-wall structures and embedded microfluidic channels have been directly printed, demonstrating that the developed glass AM technology is promising for advanced applications such as microfluidics, integrated optics, and metamaterials.

Lung Cancer Detection and Severity Analysis with a 3D Deep Learning CNN Model Using CT-DICOM Clinical Dataset

Objectives: To propose a new AI based CAD model for early detection and severity analysis of pulmonary (lung) cancer disease. A deep learning artificial intelligence-based approach is employed to maximize the discrimination power in CT images and minimize the dimensionality in order to boost detection accuracy. Methods: The AI-based 3D Convolutional Neural Network (3D-DLCNN) method is employed to learn complex patterns and features in a robust way for efficient detection and classification. The pulmonary nodules are identified by 3D Mask-R-CNN at the initial level, and classification is done by 3D-DLCNN. Kernel Density Estimation (KDE) is used to discover the error data points in the extracted features for early removal before candidate screening. The study uses the CT-DICOM dataset, which includes 355 instances and 251135 CT-DICOM images with target attributes of cancer, healthy, and severity condition (if cancer is positive). Statistical outlier detection is utilized to measure the z-score of each feature to reduce the data point deviation. The intensity and pixel masking of CT-DOCIM is measured by using the ER-NCN method to identify the severity of the disease. The performance of the 3D-DLCNN model is done using the MATLAB R2020a tool and comparative analysis is done with prevailing detection and classification approaches such as GA-PSO, SVM, KNN, and BPNN. Findings: The suggested pulmonary detection 3D-DLCNN model outperforms the prevailing models with promising results of 93% accuracy rate, 92.7% sensitivity, 93.4% specificity, 0.8 AUC-ROC, 6.6% FPR, and 0.87 C-Index, which helps the pulmonologists detect the PC and identify the severity for early diagnosis. Novelty: The novel hybrid 3D-DLCNN approach has the ability to detect pulmonary disease and analyze the severity score of the patient at an early stage during the screening process of candidates. It overcomes the limitations of the prevailing machine learning models, GA-PSO, SVM, KNN, and BPNN. Keywords: Artificial Intelligence, Disease Prediction, Lung Cancer, Deep Learning, Cancer Detection, Computational Model, 3D-DLCNN

Influence of build orientation on porosity, strength and dimensional accuracy of laser sintered polyamide porous bone scaffolds

Development of synthetic bone graft via bone tissue engineering involves seeding of patient’s stem cells onto a porous scaffold in presence of growth factors. Porosity, strength and dimensional accuracy of the porous scaffold play a vital role in this process. This work aims at ascertaining influence of build orientation on porosity, mechanical strength and dimensional accuracy of the selectively laser sintered polyamide porous scaffolds. Initially, CAD models of test specimens with pre-designed porosity were created in Solidworks® software. All the specimens were fabricated on EOSINT P395, a selective laser sintering machine, along various primary (Flat, Edge, Upright and Flat_diag) and secondary (0o, 30o, 45o, 60o and 90o) orientations. Results show that measured porosity of most of the specimens was (range: 42.89-35.26%) less than the designed porosity (41.71%). Maximum average tensile strength (16.84 MPa) was recorded for specimens printed along Flat_0o orientation. Specimens printed along Upright_90o orientation showed highest average compressive strength (8.26 MPa). Specimens printed along Flat orientation showed relatively better average impact strength. Best dimensional accuracy was obtained for specimens printed along Flat orientation.

Combined Soft Grasping and Crawling Locomotor Robot for Exterior Navigation of Tubular Structures

This paper presents the design, development, and testing of a robot that combines soft-body grasping and crawling locomotion to navigate tubular objects. Inspired by the natural snakes’ climbing locomotion of tubular objects, the soft robot includes proximal and distal modules with radial expansion/contraction for grasping around the objects and a longitudinal contractile–expandable driving module in-between for providing a bi-directional crawling movement along the length of the object. The robot’s grasping modules are made of fabrics, and the crawling module is made of an extensible pneumatic soft actuator (ePSA). Conceptual designs and CAD models of the robot parts, textile-based inflatable structures, and pneumatic driving mechanisms were developed. The mechanical parts were fabricated using advanced and conventional manufacturing techniques. An Arduino-based electro-pneumatic control board was developed for generating cyclic patterns of grasping and locomotion. Different reinforcing patterns and materials characterize the locomotor actuators’ dynamical responses to the varying input pressures. The robot was tested in a laboratory setting to navigate a cable, and the collected data were used to modify the designs and control software and hardware. The capability of the soft robot for navigating cables in vertical, horizontal, and curved path scenarios was successfully demonstrated. Compared to the initial design, the forward speed is improved three-fold.

A Method for Unseen Object Six Degrees of Freedom Pose Estimation Based on Segment Anything Model and Hybrid Distance Optimization

Six degrees of freedom pose estimation technology constitutes the cornerstone for precise robotic control and similar tasks. Addressing the limitations of current 6-DoF pose estimation methods in handling object occlusions and unknown objects, we have developed a novel two-stage 6-DoF pose estimation method that integrates RGB-D data with CAD models. Initially, targeting high-quality zero-shot object instance segmentation tasks, we innovated the CAE-SAM model based on the SAM framework. In addressing the SAM model’s boundary blur, mask voids, and over-segmentation issues, this paper introduces innovative strategies such as local spatial-feature-enhancement modules, global context markers, and a bounding box generator. Subsequently, we proposed a registration method optimized through a hybrid distance metric to diminish the dependency of point cloud registration algorithms on sensitive hyperparameters. Experimental results on the HQSeg-44K dataset substantiate the notable improvements in instance segmentation accuracy and robustness rendered by the CAE-SAM model. Moreover, the efficacy of this two-stage method is further corroborated using a 6-DoF pose dataset of workpieces constructed with CloudCompare and RealSense. For unseen targets, the ADD metric achieved 2.973 mm, and the ADD-S metric reached 1.472 mm. This paper significantly enhances pose estimation performance and streamlines the algorithm’s deployment and maintenance procedures.

Influence of the Curve of Spee on Tooth Displacement Patterns: A Finite Element Analysis at Varying Implant Heights.

Background Monocortical mini-screw-type temporary anchorage devices (TADs), or mini-screws, have significantly impacted orthodontic treatment strategies, especially in severe crowding and protrusion cases. These devices offer flexibility in placement sites, but the chosen location can considerably influence tooth displacement patterns. Key factors include the 'line of force' and the biomechanical properties of orthodontic tools. By analyzing tension distribution and three-dimensional displacements, the finite element method (FEM) provides a thorough means to comprehend these patterns. The Curve of Spee (COS) is a crucial factor potentially affecting displacement. Objective This study aimed to leverage finite element analysis (FEA) to understand the impact of varying mini-implant heights (10 mm, 13 mm, and 16 mm) on the displacements of different tooth types under a consistent force of 150 gm and compare these displacements both in the presence and absence of the COS. Materials and methods A CAD model of the jaw and teeth was developed using CT scan data and a Rexcan III 3D White Light Scanner. This model was meshed in Altair HyperMesh using tetrahedral elements, resulting in a Finite Element Model. The model incorporated various components, including teeth, the periodontal ligament (PDL), alveolar bone, brackets, a titanium mini-screw, and an archwire measuring 0.019 x 0.025 inches. Unique material properties were assigned to the PDL, and the assembly accurately replicated the clinical alignment of the archwire and brackets. Subsequently, stress and strain analyses were conducted on the model using the FEM. Results The displacement patterns of various teeth at implant heights of 10 mm, 13 mm, and 16 mm under a 150-gm force were analyzed in relation to the COS. Notably, for the central incisor, the COS significantly affected displacements in the Y and Z directions. Similarly, the Lateral Incisor and Canine exhibited marked changes in the Z direction with the presence of the COS. The Second Premolar's apex displacement showed significant variation due to the COS, while the First Molar displayed notable changes in the X direction. Generally, the presence of the COS either maintained or slightly increased Z-directional displacements across teeth, particularly at the apices. Conclusion The presence of COS significantly influences tooth displacement patterns when using mini-screws at different implant heights. Central incisors, lateral incisors, and canines are particularly sensitive to changes in the Z direction with the COS. The biomechanical analysis emphasizes the importance of considering COS in treatment planning for optimal results with mini-implants in orthodontics.

Development and implementation of a wireless-controlled robotic arm for lifting applications with 6 DOF

This paper is centered on the design and construction of a Bluetooth-controlled robotic arm with 6 degrees of freedom. It is capable of manipulating given objects as well as lifting and conveying a payload from one point to another. Any smartphone that possesses an Android operating system can be used for remote operations. This offers a background look at robotic arms, from invention to current trend as well as simplification of design to make it more accessible to robotics enthusiasts. The design process for the robotic arm is chronicled in this paper, from the working principle to the development of the kinematic equations, as well as CAD modeling and component selection. Tests are also conducted to ascertain the robot’s strength and range of capabilities. The availability of this robotic arm would serve as an indispensable learning tool for experimenting with robotics in training institutions.

Maintenance study on WCLL-TBS ancillary systems in process room

The Water-Cooled Lithium Lead Test Blanket System (WCLL-TBS) is one of the European TBS candidates for being installed and operated in ITER. The ongoing activities toward the Preliminary Design Review of the WCLL-TBS Ancillary Systems include the reallocation of their units in the reserved space, also in the view of the proper execution of the maintenance activities. Starting from the available documentation (System Design Description, Process Flow Diagrams, Process and Instrumentation Diagrams), detailed 3D CAD models have been developed for two Ancillary Systems to be installed in the Process room: the Tritium Extraction System (TES) and the Tritium Accountancy System (TAS). In the Process room (PR), the largest part of the TES process units is placed inside a Glove-box, as enclosure to avoid the contamination of the room in case of radioactive release due to failure of units. Based on the expected radioactivity content, all the TAS units are placed inside the Glove-box. Maintainability studies have been performed, focusing on the preventive (i.e. planned) and corrective (i.e. required by failures) maintenance tasks on the units installed inside the Glove-box. They were based on the 3D CAD models and supported using Virtual Reality as intuitive and immersive human-computer interface. They provided insights for the iterative improvement and consolidation of the Systems design and information for the evaluation of their availability.

Reinforcement learning for block decomposition of planar CAD models

AbstractThe problem of hexahedral mesh generation of general CAD models has vexed researchers for over 3 decades and analysts often spend more than 50% of the design-analysis cycle time decomposing complex models into simpler blocks meshable by existing techniques. The decomposed blocks are required for generating good quality meshes (tilings of quadrilaterals or hexahedra) suitable for numerical simulations of physical systems governed by conservation laws. We present a novel AI-assisted method for decomposing (segmenting) planar CAD (computer-aided design) models into well shaped rectangular blocks. Even though the simple examples presented here can also be meshed using many conventional methods, we believe this work is proof-of-principle of a AI-based decomposition method that can eventually be generalized to complex 2D and 3D CAD models. Our method uses reinforcement learning to train an agent to perform a series of optimal cuts on the CAD model that result in a good quality block decomposition. We show that the agent quickly learns an effective strategy for picking the location and direction of the cuts and maximizing its rewards. This paper is the first successful demonstration of an agent autonomously learning how to perform this block decomposition task effectively, thereby holding the promise of a viable method to automate this challenging process for more complex cases.

Comprehensive design and analysis of a 300L steel fuel tank for heavy off-road vehicles: numerical and experimental insights

Introduction: This study presents a comprehensive design and analysis of a 300L steel fuel tank intended for heavy off-road vehicles. The design process integrates numerical simulations and experimental investigations to optimize the tank's performance and durability under various operating conditions.Methods: The design methodology involves CAD model optimization, numerical analysis setup, and experimental validation. CAD model optimization simplifies the tank geometry while retaining structural integrity. Numerical analysis setup includes defining boundary conditions, meshing strategies, and simulation parameters. Experimental validation entails testing the tank under dynamic loading conditions to assess its structural response.Results: Numerical simulations reveal insights into stress distribution, deformation behavior, and fluid dynamics within the tank. Experimental tests confirm the numerical predictions and provide valuable data for model validation. Key results include stress concentrations in critical areas, deformation patterns under different loading conditions, and fluid flow characteristics.Discussion: The integrated approach combining numerical simulations and experimental tests offers a comprehensive understanding of the fuel tank's behavior. Findings highlight areas for design improvement, such as reinforcement of stress-prone regions and optimization of fluid flow dynamics. The study contributes to enhancing the performance, reliability, and safety of fuel tanks for heavy off-road vehicles.

A comparative study for the assessment of marker-less mixed reality applications for the operator training

ABSTRACT With the rising concept of Industry 5.0, the worker’s needs and well-being are placed at the center of the production process. The use of extended reality can be exploited to provide the operator with interactive training, allowing independent, step-by-step learning in the real environment, with instructional digital contents, superimposed over the machinery in the workplace. This kind of training promotes the operator’s skills, and consequently empowers the industrial competitiveness. The aim of this paper is to assess and compare the effectiveness of two different marker-less mixed reality (MR) applications to train the operator in the wire harness activities over a tractor’s drivetrain. An application based on Azure Spatial Anchors by Microsoft and another one based on the CAD model of the tractor’s drivetrain have been developed and tested through the comparison with the traditional paper-based instructions. On-field trials have been accomplished with 10 end-users. User experience, usability, perceived workload, and training effectiveness have been assessed through specific questionnaires and by analyzing user performances. Even if the Anchors-based app showed better outcomes in terms of effectiveness and acceptability, both MR applications resulted in good usability. Operators’ willingness of using this technology as a standard tool for training and support emerged.

Analysis of Influence of Sand Matrix on Properties of Moulding Compounds Made with Furan Resin Intended for 3D Printing

Binder jetting (BJ) sand printing is a 3D printing process in which a sand mould or sand core is produced from an STL file. A single layer of a sand matrix consisting of one or more grains in height of sand is applied to a worktable, and then a liquid resin or binder is applied to bond the grains together. This process is repeated until the final result matches the CAD model. The sand matrix is the main component of ceramic cores and moulds. The present study aims to demonstrate the influence of the matrix used on the properties of the resulting moulding sand. Three types of sand matrices were selected for the study. The first was a quartz matrix for 3D printing with binder jetting; this is characterised by a sharp geometry that allows for proper layering during printing. Ordinary quartz sand was also used for the study; this type of sand is usually used for the production of sand cores in the hotbox process, among other things. The shape of this sand is irregular. The last matrix to be tested was Cerabeads sand; this was selected because its spherical geometry clearly distinguishes it from the other two matrices. The matrices were analysed for their grain sizes. Scanning electron microscope images were also taken to compare the geometries and chemical compositions of the respective matrices. In presented research utilises a sand matrix for the production of self-curing compounds with furan resin dedicated for binder jetting 3D printing. The moulding masses were produced in a laboratory circulation mixer. The laboratory moulds were produced with wooden core boxes and pre-compacted by vibration. The samples from the matrix for the 3D printing were produced using the binder jetting method. The samples were produced to determine the flexural strength, tensile strength, gas permeability, hot distortion, and apparent density. It was not possible to carry out tests for the Cerabeads sand, as the obtained moulds were too brittle to perform adequate tests. Tests with the other matrices have shown that the shape and size of the matrix affect the apparent density and gas permeability.

FRAME DESIGN OF INLINE SKATES MADE BY ADDITIVE TECHNOLOGY

The aim of the article was to investigate the possibility of topological optimization (TO) of the inline skate frame manufactured through the Powder Bed Fusion (PBF) method of AISi10Mg-0403, an Additive Manufacturing (AM) technique. The study's core objective was to leverage The Altair Inspire software to re-envision the initial CAD model, culminating in an organic and bionic frame design. Incorporating comprehensive load analysis, the research considered various load scenarios, including static mass, dynamic forces, and acceleration during cornering, to ascertain the frame's strength and stability. Topological optimization was excluded within a defined design space, preserving critical functional elements while enhancing performance. The first part of the article is devoted to defining the concepts and nature of AM metallic materials. The practical part follows, in which the design of the skate frame is specified with specific requirements and the procedure of individual steps needed to create its final CAD Model. The work concludes by describing the preparation of the designed optimized frame construction.

A Survey of 6DoF Object Pose Estimation Methods for Different Application Scenarios.

Recently, 6DoF object pose estimation has become increasingly important for a broad range of applications in the fields of virtual reality, augmented reality, autonomous driving, and robotic operations. This task involves extracting the target area from the input data and subsequently determining the position and orientation of the objects. In recent years, many new advances have been made in pose estimation. However, existing reviews have the problem of only summarizing category-level or instance-level methods, and not comprehensively summarizing deep learning methods. This paper will provide a comprehensive review of the latest progress in 6D pose estimation to help researchers better understanding this area. In this study, the current methods about 6DoF object pose estimation are mainly categorized into two groups: instance-level and category-level groups, based on whether it is necessary to acquire the CAD model of the object. Recent advancements about learning-based 6DoF pose estimation methods are comprehensively reviewed. The study systematically explores the innovations and applicable scenarios of various methods. It provides an overview of widely used datasets, task metrics, and diverse application scenarios. Furthermore, state-of-the-art methods are compared across publicly accessible datasets, taking into account differences in input data types. Finally, we summarize the challenges of current tasks, methods for different applications, and future development directions.

3D isogeometric indirect BEM solution based on virtual surface sources on the boundaries of Helmholtz acoustic problems

A solution for 3D Helmholtz acoustic problems is introduced based on an indirect boundary element method (indirect BEM) coupled with isogeometric analysis (IGA). The novelty of this work arises from using virtual surface sources placed directly on the scatterer boundaries, producing robust results. These virtual surface sources are discretized by the same Non-Uniform Rational B-Splines (NURBS) approximating the scatterer CAD model. This allows modeling of general irregular geometries. The proposed solution has the same features of BEM approaches, which do not need any domain discretization or truncation boundaries at the far-field. It shows an additional merit by arranging the linear system of equations directly depending on a single coefficient matrix, consuming less computational time compared to other BEM methods. A Greville abscissae collocation scheme is proposed with offsets at C0\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$C^0$$\\end{document}-continuities. This collocation scheme allows for easy evaluation for both free-terms and normals at the collocation points. The performance of the proposed solution is discussed on 3D numerical exterior problems and compared against other BEM methods. Then, the practical interior muffler problem with internal extended thin tubes is studied and the obtained results are compared against other numerical methods in addition to the available experimental data, showing the capability of the proposed solution in handling thin-walled geometries.

CAD Modeling Process in Animation Design Using Data Mining Methods

CAD Modeling Process in Animation Design Using Data Mining Methods

(140) What Spatulation Angle Most Optimally Increases Anastomosis Circumference While Maintaining The Flap Length: Width Ratio To < 2:1? Three-Dimensional Modelling Applications for Surgical Spatulation for Urologic Reconstruction

Abstract Introduction Spatulation is a surgical technique used to anastomose tubular structures in urology, including the urethra, ureter, and in transgender surgery, the neovaginal canal-end to a peritoneal pouch. This is critical in restoring normal function with a water-tight repair, and reducing the risk of stricture-formation secondary to post-operative scarring at the site of repair within a tubular structure. Considerations such as the optimization of the length-to-width ratio of the spatulated tube to <2:1 have been described as a means of ensuring adequate blood supply to the distal-most spatulated end, however, no studies to date have evaluated the optimal angle of spatulation to achieve this. We used CAD models to 3-D print tubular structures that would maintain their internal measurements as we conducted our analysis to ascertain the optimal angles of spatulation. (Figure 1a) Objective 1) To ascertain the optimal angle of spatulation using 3-D tubular structures maintain a 2:1 ratio of length to width for consideration during operative repair of tubular structures. Methods Three-dimensional CAD files of hollow, tubular structures were designed and printed with an internal circumference of 110mm. Each of the four models were then cut at 30°, 45°, 60°, and 75° to represent each of the different incision angles (Figure 1b). The inner circumferences and added length of each of the resulting flaps were measured on each CAD models. Using this information, the optimal angle of spatulation was calculated using geometric and mathematical analysis. We used the accepted convention of the 2:1 length to width ratio to ensure sufficient perfusion to the distal-most point of the flap as the limit when calculating the optimal angle of spatulation. Results The inner circumferences and added length is shown in Figure 1c. Overall, as expected, increasing the angle of spatulation from 30° to 75° increased the circumference of the anastomotic site and decreased the risk of stricture-formation post-operatively. It was noted that as the angle of spatulation increases, the inner circumference and the length of the resulting flap both increase exponentially. The angle of spatulation corresponding to the widely accepted criterion of 2:1 for the Length-to-Width ratio is 63.4°. Conclusions Our findings show that as the angle of spatulation increases, the circumference of the spatulation site increases. However, a competing limit to increasing spatulation-angle is that the spatulated ends become increasingly narrow and far from the source of the blood vessels, which compromises the blood supply to the distal tip-ends. To help ensure adequate perfusion of the spatulated limbs, it is desirable to maintain a Length-to-Width ratio of <2:1. Our work finds that the maximum spatulation angle that maintains Length-to-Width at <2:1 is 63.4 degrees. Disclosure No.

Analysis of the Technical Accuracy of a Patient-Specific Stereotaxy Platform for Brain Biopsy.

The use of stereotactic frames is a common practice in neurosurgical interventions such as brain biopsy and deep brain stimulation. However, conventional stereotactic frames have been shown to require modification and adaptation regarding patient and surgeon comfort as well as the increasing demand for individualized medical treatment. To meet these requirements for carrying out state-of-the-art neurosurgery, a 3D print-based, patient-specific stereotactic system was developed and examined for technical accuracy. Sixteen patient-specific frames, each with two target points, were additively manufactured from PA12 using the Multi Jet Fusion process. The 32 target points aim to maximize the variability of biopsy targets and depths for tissue sample retrieval in the brain. Following manufacturing, the frames were measured three-dimensionally using an optical scanner. The frames underwent an autoclave sterilization process prior to rescanning. The scan-generated models were compared with the planned CAD models and the deviation of the planned target points in the XY-plane, Z-direction and in the resulting direction were determined. Significantly lower (p < 0.01) deviations were observed when comparing CAD vs. print and print vs. sterile in the Z-direction (0.17 mm and 0.06 mm, respectively) than in the XY-plane (0.46 mm and 0.16 mm, respectively). The resulting target point deviation (0.51 mm) and the XY-plane (0.46 mm) are significantly higher (p < 0.01) in the CAD vs. print comparison than in the print vs. sterile comparison (0.18 mm and 0.16 mm, respectively). On average, the results from the 32 target positions examined exceeded the clinically required accuracy for a brain biopsy (2 mm) by more than four times. The patient-specific stereotaxic frames meet the requirements of modern neurosurgical navigation and make no compromises when it comes to accuracy. In addition, the material is suitable for autoclave sterilization due to resistance to distortion.

Design and Strength Analysis of a New Construction of a Sweeper with an Independent Surface Copying System Dedicated to Small Loaders and Front Loaders

Most enterprises and farms have paved parking lots, yards, warehouses, or sidewalks that need to be cleaned or cleaned. There are many sweepers available on the Polish and European markets, but there is still a lack of a solution that would be mounted on pallet forks and would have an independent copying system to support sweeping surfaces with different inclinations. The aim of the work was to develop a conceptual design for a new sweeper equipped with an independent surface copying system dedicated to small loaders and front loaders, as a well as strength analysis of the main frame. The conceptual design included an analysis of available solutions, development of a 3D CAD model of the new sweeper, and a detailed strength analysis of the sweeper’s main frame using the finite element method (FEM). The sweeper model was made in the Autodesk Inventor program, while the FEM strength analysis was made in the Siemens NX program. The designed frame model did not have nodes in which the stresses would be greater than 25% of the allowable stress in the material structure and 33% of the maximum allowable stress in the structure of the joints. The sweeper developed new design fulfills all the assumed functions and has a good chance of application.