3D Laser Scanning Research Articles

Mathematical Modeling for Robot 3D Laser Scanning in Complete Darkness Environments to Advance Pipeline Inspection

This paper introduces an autonomous robot designed for in-pipe structural health monitoring of oil/gas pipelines. This system employs a 3D Optical Laser Scanning Technical Vision System (TVS) to continuously scan the internal surface of the pipeline. This paper elaborates on the mathematical methodology of 3D laser surface scanning based on dynamic triangulation. This paper presents the mathematical framework governing the combined kinematics of the Mobile Robot (MR) and TVS. It discusses the custom design of the MR, adjusting it to use of robustized mathematics, and incorporating a laser scanner produced using a 3D printer. Both experimental and theoretical approaches are utilized to illustrate the formation of point clouds during surface scanning. This paper details the application of the simple and robust mathematical algorithm RANSAC for the preliminary processing of the measured point clouds. Furthermore, it contributes two distinct and simplified criteria for detecting defects in pipelines, specifically tailored for computer processing. In conclusion, this paper assesses the effectiveness of the proposed mathematical and physical method through experimental tests conducted under varying light conditions.

Virtual Reality Scenario Analysis of Art Design Taking into Account Interactive Digital Media Pattern Generation Technology

In art design, 3D printing technology is crucial, and more and more creators conceive scenes using 3D modeling software to get a three-dimensional and beautiful work. Due to the large amount of noise and redundant points in the raw data collected during the modeling process, the generation speed and rendering effect of 3D models are reduced. Given the above problems, the study designed an interactive 3D lightweight modeling system based on the combination of hand-drawn sketching and laser 3D scanning based on the streamlined algorithm. The experimental results showed that when the hand-drawn speed was 300, the number of triangular slices, model size, and time required to generate the model of the hand-drawn sketching model based on the streamlined algorithm were reduced by 67.39%, 65.48%, and 63.79%, respectively. In the real-time point cloud data streamlining process of the laser 3D scanning model, the point cloud data reduction ratio and the streamlining goodness index of the point cloud streamlining algorithm are 71.99% and 3.06%, respectively. The system performance is robust, and the data processing speed and rendering effect are good.

SLAM for Indoor Mapping of Wide Area Construction Environments

Abstract. Simultaneous localization and mapping (SLAM), i.e., the reconstruction of the environment represented by a (3D) map and the concurrent pose estimation, has made astonishing progress. Meanwhile, large scale applications aiming at the data collection in complex environments like factory halls or construction sites are becoming feasible. However, in contrast to small scale scenarios with building interiors separated to single rooms, shop floors or construction areas require measures at larger distances in potentially texture less areas under difficult illumination. Pose estimation is further aggravated since no GNSS measures are available as it is usual for such indoor applications. In our work, we realize data collection in a large factory hall by a robot system equipped with four stereo cameras as well as a 3D laser scanner. We apply our state-of-the-art LiDAR and visual SLAM approaches and discuss the respective pros and cons of the different sensor types for trajectory estimation and dense map generation in such an environment. Additionally, dense and accurate depth maps are generated by 3D Gaussian splatting, which we plan to use in the context of our project aiming on the automatic construction and site monitoring.

Effective Denoising Algorithms for Converting Indoor Blueprints Using a 3D Laser Scanner

This paper focuses on converting complex 3D maps created by LiDAR and SLAM technology into simple 2D maps to make them easier to understand. While 3D maps provide a lot of useful details for robots and computer programs, they can be difficult to read for humans who are used to flat maps. We developed a new system to clean up these 3D maps and convert them into intuitive and accurate 2D maps. The system uses three steps designed to correct different kinds of errors found in 3D LiDAR scan data: clustering-based denoising, height-based denoising, and Statistical Outlier Removal. In particular, height-based denoising is the method we propose in this paper, an algorithm that leaves only indoor structures such as walls. The paper proposes an algorithm that considers the entire range of the point cloud, rather than just the points near the ceiling, as is the case with existing methods, to make denoising more effective. This makes the final 2D map easy to understand and useful for building planning or emergency preparedness. Our main goal is to map the interior of buildings faster and more effectively, creating 2D drawings that reflect accurate and current information. We want to make it easier to use LiDAR and SLAM data in our daily work and increase productivity.

Acoustic emission and fracture morphology characteristics of thermal-damage granite under mixed mode I/III loading

To explore the fracture morphology and acoustic emission characteristics of thermally damaged granite under mixed mode I/III loading, a series of heat treatment and mixed mode I/III loading tests were conducted on edge-notched disc bend (ENDB) granite samples. First, the thermal damage samples’ strength and crack opening displacement were analyzed. Subsequently, based on 3D laser scanning technology, the fracture morphology of the sample was studied, and the fractal dimension was calculated. Then, the samples’ acoustic emission characteristics were discussed, including the ringing count, b value, spectrum signature, and AF-RA. Finally, an acoustic early warning index was proposed based on the critical slowing down theory, and the influence of temperature on the early warning effect was analyzed. The results show that under mixed mode I/III loading, the samples formed an antisymmetric curved surface with out-of-plane torsion. As the thermal damage effect is enhanced, the peak strength decreases linearly, and the fractal dimension increases linearly. The failure mode changes from sudden instability to progressive instability. Shear cracks gradually dominate the sample failure. The peak frequency signal of the sample is mainly distributed between 80 kHz and 400 kHz. The appearance of the sudden drop in the b value and a zero-frequency signal has an early warning effect. The quadratic function can describe the relationship between warning time and temperature. As the temperature increases, the deterioration effect of historical loading on the sample is enhanced, the development time of sample failure is prolonged, and the early warning effect is better.

Mechanical behaviour of weakly filled granite and a unified evaluation method for macro-fine-micro multi-scale fracture characteristics

The mechanical properties of weakly filled rock are critical for engineering rock stability control. With the help of 3D DIC (Digital Image Correlation) and AE (Acoustic Emission) monitoring system, and the industrial CT (Computed Tomography), 3D laser scanning and SEM (Scanning Electron Microscope) technology, the mechanical behaviour and fracture characteristics of granite with different inclination angles of planar weak filling were analyzed comprehensively. Firstly, the influence law of the inclination angle of planar weak filling on the basic mechanical properties of the specimens was investigated, and it was confirmed that the specific angle had an obvious weakening effect on the specimen’s ability to resist deformation. Then, the spatial deformation field evolution and failure mode of the specimen were analysed, and it was found that when the inclination angle increased from 0° to 90°, the failure mode of the specimen will gradually change from “Y”-shaped shearing and splitting mixed failure to “chain” splitting failure, and then to overall splitting failure. Then, the spatial distribution of the micro-fracture event was analysed, and the results show that the spatio-temporal evolution and distribution characteristics of the micro-fracture events, the distribution characteristics of the spatio-temporal evolutionary local enlargement zone of the deformation field and the spatial distribution of the main fracture surface at the time of final failure are highly consistent and correlated. The spatio-temporal evolution and distribution characteristics of micro-fracture events provide important references for predicting the location, time and degree of spatial failure in weakly filled rock mass. Finally, based on the fractal theory, the fracture characteristics within the multiscale of the specimen were analysed, and the method of evaluating the unity of the multiscale fracture characteristics of the rock mass was summarised and given.

FEATURES OF COMBINING THE RESULTS OF 3D LASER SCANNING FROM DIFFERENT STATIONS USING MAGNETIC SPHERES

3D laser scanning is becoming an increasingly important technology in the modern world, opening up endless possibilities for obtaining accurate geometric parameters of various objects. So, due to its efficiency and accuracy, this technology is becoming indispensable in such industries as surveying, construction support, executive surveying, geodetic monitoring, and others. However, despite the many advantages of laser scanning, it has a limitation that can significantly affect the results, namely the algorithm for stitching individual scans into a single-point cloud. Most scanners do not have built-in capabilities to stitch together scan results from multiple stations automatically. Therefore, obtaining a single-point cloud requires using alternative methods. Modern laser scanner companies offer a variety of models with unique technical characteristics. The right choice of scanner functionality is crucial when performing various technological tasks throughout the entire process, from scanning to obtaining the result. The technical parameters of laser scanners, such as measurement accuracy, maximum scanning range, and scanning speed, vary depending on the type of objects scanned and the necessary results. The use of magnetic spheres becomes an essential aspect of ensuring scanning accuracy. They facilitate stitching data from different stations and allow automated search for stitching points, simplifying data processing. An algorithm built into Trimble RealWorks software automatically detects magnetic spheres in the point cloud. It uses an appropriate transformation to join two adjacent scans from different stations if more than three identical spheres are present. The article aims to study the peculiarities of combining the results of 3D laser scanning from several stations using magnetic spheres. It discusses the analysis of the technical parameters of the Trimble TX6 laser scanner, variations in the use of magnetic spheres to ensure the accuracy of combining scanning results, and the advantages and disadvantages of this approach. Keywords: 3D laser scanning, magnetic spheres, stitching algorithm, point cloud, Trimble RealWorks.

TECHNOLOGY FOR COMBINING THE RESULTS OF 3D LASER SCANNING FROM DIFFERENT STATIONS USING PLANE MARKS

3D laser scanning is a promising technology gaining popularity and active use worldwide. One of the advantages of 3D laser scanning is the speed of the scanning process and processing of the results. Compared to other geodetic instruments, this technology allows for displaying large objects in a much shorter time and more efficiently. For example, at the construction stage of an industrial plant, scanning enables monitoring the shapes and sizes of all its elements in real time, which is critical for controlling and optimising construction processes. Another important aspect is the geometric complexity of objects. Many objects can have complex shapes or similar elements of considerable length. When combining scanning results from different stations, it is necessary to ensure the accuracy and correct geometry of the object. To combine scan results, designated markers in the form of spheres and plane marks are used. However, unlike spheres, plane markers can be more convenient and economical. In addition, they can be left on the object for a long time, which significantly simplifies the additional scanning or data correction. It is also notable that in our time, the development of laser scanning technologies has led to new scanners that can automatically stitch together scan results by using advanced technology to track characteristic points in the environment. Despite the significant advantages of this new technology in terms of efficiency and accuracy, it is worth noting that it is rather expensive. Accordingly, scanners that do not have this advanced technology rely on alternative methods of stitching together scan results, such as placing plane marks on the object. The article aims to develop a technology for combining the results of 3D laser scanning from different stations using plane marks. The article considers the evaluation of the technical characteristics of the Trimble TX6 laser scanner, the analysis of options for using plane marks to ensure scanning accuracy, and the identification of the advantages and disadvantages of this method. Keywords: 3D laser scanning, plane marks, stitching algorithm, point cloud, Trimble RealWorks.

Experimental investigation on fractal mechanism and shear failure characteristics of cement mortar at different curing ages

In this paper, the NMR and direct shear tests were conducted successively on cement mortar specimens with different curing ages (7 days, 14 days and 28 days). The porosity, shear strength, shear stiffness and shear energy of cement mortar are measured and analyzed through interpreting the pore distribution patterns and their corresponding fractal dimensions. The cross-sections of shear surface were characterized into point cloud data via 3D laser scanning and quantified by three dimensionless parameters (the root mean square value of the first derivative, root mean square value and joint roughness coefficient). The grey relation analysis (GRA) method and principal component analysis (PCA) is employed to analyze the relationship between the pore structures (i.e., gel pores, transition pores, capillary pores and pores or cracks) and distribution and the fractal dimensions. The results indicate that the shear peak strength is linearly correlated with the joint roughness coefficient. Compared to the fractal characteristics of pore size (T2 spectra) and pore distribution (MRI), we demonstrated that there is a strong correlation between the peak shear strength and the fractal dimension of shear fracture surface, which suggests that the quantitative characterization of internal pores and shear strength variations in cement mortar specimens can be achieved through the numerical values of fractal dimensions.

Practicalities of Incorporating 3D Laser Scanning with BIM in Live Construction Projects: A Case Study

The integration of laser scanning technology and Building Information Modelling (BIM) processes offers a transformative approach to managing the complexities in live construction projects. This paper aims to explore the significant impacts of incorporating laser scanning and BIM on construction projects in terms of as-built models, information management, and overall project performance utilising case study analysis of a building that was not BIM-based. The research scope is defined by the need to investigate the integration of laser scanning and BIM in live construction projects. It details the data acquisition process, challenges encountered due to site obstructions, and the methodologies employed for spatial modelling procedures. Key findings reveal that such integration can significantly enhance the accuracy of data collection and improve project outcomes. Results also identify the need for specialised equipment and skills for the effective implementation of such integrations. The research concludes by offering a practical approach to enhancing construction processes, from design to maintenance. This paper contributes to the body of knowledge by providing a detailed analysis of the practical application of laser scanning and BIM in a live construction project, offering insights into the benefits, challenges, and future directions for integrating these technologies in the construction industry.

Behavior of wire arc additively manufactured 316L austenitic stainless steel single shear bolted connections

This paper aims to investigate the behavior of single shear bolted connections made of wire arc additively manufactured 316L austenitic stainless steel. A set of 44 wire arc additive manufacturing (WAAM) 316L austenitic stainless steel single shear bolted connections were included with consideration of various bolt positions, surface conditions and loading orientations respective to the printing layer direction. The geometric dimensions of the WAAM austenitic stainless steel plates were measured with the assistance of non-contact 3D laser scanning prior to tensile testing. Monotonic tensile tests were carried out to investigate the load-deformation responses, failure patterns and resistances determined by both the deformation and strength criteria of the single shear bolted connections. The effects of geometric and printing parameters on the single shear bolted connections were analyzed. Due to the absence of codified design provisions for WAAM austenitic stainless steel bolted connections, the suitability of the existing design rules originally developed for traditionally manufactured carbon steel and stainless steel bolted connections was examined. Design resistances calculated by the Eurocode 3 (prEN 1993-1-8 and prEN 1993-1-4), the American Specification (ANSI/AISC 370-21) as well as the prevalent design recommendations proposed in existing literature were compared with the obtained experimental results. It is shown that the abovementioned design methods offer conservative predictions for the resistances of WAAM 316L austenitic stainless steel single shear bolted connections. Further study is needed to improve the accuracy of design resistance predictions.

Three-Dimensional-Scanning of Pipe Inner Walls Based on Line Laser.

In this study, an innovative laser 3D-scanning technology is proposed to scan pipe inner walls in order to solve the problems of the exorbitant expenses and operational complexities of the current equipment for the 3D data acquisition of the pipe inner wall, and the difficulty of both the efficiency and accuracy of traditional light stripe-center extraction methods. The core of this technology is the monocular-structured light 3D scanner, the image processing strategy based on tracking speckles, and the improved gray barycenter method. The experimental results demonstrate a 52% reduction in the average standard error of the improved gray barycenter method when compared to the traditional gray barycenter method, along with an 83% decrease in the operation time when compared to the Steger method. In addition, the size data of the inner wall of the pipe obtained using this technology is accurate, and the average deviation of the inner diameter and length of the pipe is less than 0.13 mm and 0.41 mm, respectively. In general, it not only reduces the cost, but also ensures high efficiency and high precision, providing a new and efficient method for the 3D data acquisition of the inner wall of the pipe.

Towards an objective assessment of tree vitality: a case study based on 3D laser scanning

Key messageAnalyzing fine branch length characteristics in beech trees using single-tree QSMs derived from laser scanning reveals insights into drought-induced changes in vitality, which include branch shedding and reduced shoot growth.Climate change causes increasing temperatures and precipitation anomalies, which result in deteriorations of tree health and declines in ecosystem services of forests. It is therefore crucial to monitor tree vitality to preserve forests and their functions. However, methods describing tree vitality in situ are lacking reproducibility or are too laborious. Thus, we tested a laser-scanning based approach, assuming that an objective measurement of a tree’s outer shape should reveal changes according to tree vitality. QSMs of similarly sized beech trees from stands with varying degrees of drought damage were used. Absolute and relative fine branch lengths, their ratio to lower order branches’ lengths and their progressions over relative height were targeted to identify fine branch dieback and reduced growth. The absolute fine branch length was significantly lower for less vital beech trees, especially within the upper crown, leading to a less top-heavy vertical distribution of fine branches and a reduced fine-to-base order branch length ratio. Hence, height-dependent characteristics of fine branch lengths differed between vitalities. We conclude that using fine branch length characteristics derived from QSMs can be helpful in vitality assessments of beech trees. Still, uncertainties with regard to the plotwise assessment and problems with QSM quality are present.

Fracture behaviors of sustainable recycled aggregate concrete under compression-shear loading: Laboratory test, numerical simulation, and environmental safety analysis

A series of compression-shear tests were carried out to investigate the shear failure of sustainable recycled aggregate concrete, and shear failure surfaces were scanned by a 3D laser scanner. The effect of recycled coarse aggregate (RCA) replacement rates and normal stresses on the shear strength, failure mode, and fracture morphology were analyzed. Meanwhile, discrete element method was used to study shear behaviors at a mesoscale. Finally, the carbon emission was calculated to evaluate the effect of RCA on the environment. The result shows that the shear strength, cohesion c, and internal friction angle φ all decrease as the RCA replacement rate increases. The shear damage of RAC can be aggravated by increasing the RCA replacement rate. Fractal dimension and joint roughness coefficient of shear failure surface tend to increase with increasing RCA replacement rate and normal stress. In addition, more microcracks can be found in coarse aggregate with the increase in RCA replacement rate, and the increasing normal stress can cause more microcracks. Given the nonlinear development of stress-displacement, a modified nonlinear constitutive model is proposed. Finally, the total carbon emissions of recycled aggregate concrete are calculated considering production, transportation, and construction, the carbon emission of 100% sustainable recycled aggregate concrete is 10.2% less than that of 100% natural aggregate concrete.

ПЕРСПЕКТИВИ ТА МОЖЛИВОСТІ БУДІВНИЦТВА МОСТІВ ЗІ ЗМЕНШЕНОЮ КІЛЬКІСТЮ ПРОМІЖНИХ ОПОР НА АВТОМОБІЛЬНИХ ДОРОГАХ УКРАЇНИ ІЗ ЗАСТОСУВАННЯМ СУЧАСНИХ ТЕХНОЛОГІЙ

A certain number of urban overpasses in Ukraine were built in the 1950s and 1960s with short spans and a large number of intermediate piers (e.g., Beresteyskyi overpass in Kyiv). The presence of intermediate piers on the roadway creates an emergency situation due to the disappearing lane before entering the structure on both sides, which leads to the accumulation of cars during rush hour. Such overpasses require reconstruction, which should include a reduction in the number of intermediate piers. As part of pre-design surveys during the reconstruction or construction of new overpasses, it is advisable to conduct laser scanning of the surrounding area to ensure the most accurate reflection of the existing infrastructure, harmonious interaction of the structure with the terrain, optimization of earthworks and use of construction materials. The use of laser scanning is a modern way to control construction and is in demand around the world. Introduction. This article reveals the need to reconstruct urban overpasses with a large number of intermediate piers to avoid the formation of accident-prone areas at the entrances to the structure. Urban bridges and overpasses require a special approach to their design and construction, as in these conditions it is recommended to take into account the aesthetic component, which includes architecturally expressive design solutions. The article presents proposals for the design of such an overpass using laser 3D scanning, which allows for a more detailed study of the design site and simplifies the control of construction work. Problem statement. The presence of intermediate piers on the roadway under overpasses creates an emergency situation due to the disappearing lane, as well as the accumulation of cars during rush hour.

Application of 3D laser scanning technology for mapping and accuracy assessment of the point cloud model for the Great Achievement Palace heritage building

Heritage buildings represent history and act as vessels of human civilisation. The significance of these architectural phenomena increases as society increases, which renders their preservation and ethical use increasingly crucial. Hence, preserving heritage buildings is necessary for societal benefit. The accuracy of three-dimensional (3D) point cloud models of heritage buildings is important to their digital conservation. Traditional mapping methods typically require more time and human resources. Furthermore, the outcome is subject to measurement omissions, errors, and other issues, which are contrary to the protection of the object measured. The complex elements of ancient Chinese architecture render it challenging for traditional measuring techniques to accurately capture spatial structural information. The 3D laser scanning technology is a novel technology to obtain 3D data rapidly. In this paper, the Great Achievement Palace of the Confucian Temple in Yuci District, Jinzhong City, Shanxi Province, was used as an example to examine the application of 3D laser scanning technology to acquire point cloud models of heritage buildings. Field data collection for architectural heritage using 3D laser scanning technology requires measuring station setting analysis to ensure effect accuracy while considering the elements of target location and quantity. For the 3D point cloud model of the Great Achievement Palace, error analysis and accuracy assessment were conducted on the quality elements of alignment accuracy between scanning stations, point cloud model reliability, point cloud data noise condition, and whether the point cloud data were stratified. The findings demonstrated that the improved method quickly and accurately acquired 3D point cloud model data and obtained realistic spatial data models of the heritage building.

Optimization of Blasting Parameters Considering Both Vibration Reduction and Profile Control: A Case Study in a Mountain Hard Rock Tunnel

The number of excavated tunnels is increasing day by day, and the corresponding engineering scale is also getting increasing. Safe, efficient, and economically beneficial tunnel construction methods are indispensable in the process of crossing mountains and steep ridges in the southwest region. However, behind the improvement of transportation infrastructure in Southwest China is the support provided by the rapid development of blasting industry engineering technology in China. In the process of tunnel construction using the drilling and blasting method, in addition to blasting vibration disasters the phenomenon of overbreak and underbreak caused by blasting construction is a prominent problem. This phenomenon not only affects the safety and stability of the tunnel excavation but also seriously increases the construction cost. Based on a short mountain hard rock tunnel project in southwest China, this paper studies the effect of blasting construction on the blasting vibration of adjacent structures and the influence of tunnel contour forming quality. Through the monitoring and analysis of in situ blasting vibration, the Sadowski formula is used to study the attenuation law of blasting vibration velocity in different tunnel sites, which provides a theoretical basis for tunnel blasting vibration control. This article compares the use of overbreak and underbreak value with the traditional method to determine the degree of overbreak and underbreak. It introduces the analysis of contour section fractal dimension value and uses fractal theory in the Python image processing module to accurately and quantitatively describe the problems of tunnel overbreak and underbreak. The feasibility and accuracy of this method have been verified, by combining the total station and 3D laser scanner results of overbreak and underbreak measurements of the Brenner Base Tunnel and a short hard rock tunnel in a mountainous area of southwestern China. The blasting scheme was optimized from the aspects of cut hole form, detonator interval time, and peripheral hole charge structure, and the rationality of the optimized scheme was verified according to the on-site blasting experiments. It has a profound influence on strengthening the protection of adjacent tunnel structures and improving the economic benefit of mountain highway projects.

Using Dynamo for Automatic Reconstruction of BIM Elements from Point Clouds

Using Dynamo for Automatic Reconstruction of BIM Elements from Point Clouds

Interlocking characteristic and its correlation with interlayer shear strength in typical double-layered asphalt systems

ABSTRACT Interlayer bonding is crucial to maintaining the structural integrity of asphalt pavement structures. Addressing a crucial research gap, this study uniquely investigated the impact of interface morphology on interlocking properties and interlayer shear strength in three typical double-layered asphalt systems: AC-13/AC-20, SMA-13/AC-20, and OGFC-13/AC-20. Through the innovative application of nondestructive separation technology and three-dimensional (3D) laser scanning, interface morphology characteristics were thoroughly analyzed. This approach enabled the detailed extraction of texture parameters, unveiling the complex relationship between interface morphology and interlayer bonding strength. Interface shear tests further assessed the difference in shear strength, revealing significant differences in texture characteristics influenced by the mineral size variance in the upper layer. This analysis led to the development of a predictive model for interlayer shear strength based on morphological characteristics, offering a new tool for approximating the shear bonding condition, despite challenges in capturing the complex interaction between interface morphology and interlocking effects. The comprehensive examination of 3D interface morphology, combined with the shear strength analysis, clarified the mechanisms of interlayer bonding in relation to interface morphology. This breakthrough provides essential insights into the role of interface morphology in bonding efficacy and represents a significant advancement in understanding of interlayer bonding mechanisms.

Improved pass-through dimensionality reduction for point cloud contour extraction

Obtaining a point cloud model that considers the overall information of large steel components as well as the local information of bolt holes is an important approach for the virtual assembly of large steel structures. A point cloud extraction method to improve the uniformity of the dimensionality reduction distribution is presented. Firstly, point cloud data characterising the overall information of a large-size component and local information of the bolt-hole group are obtained by combining vertical three-dimensional (3D) laser scanning and handheld 3D laser scanning. The point cloud is then triaxially equidistant and reduced in dimension based on improved straight-pass filtering and the corner point cloud is extracted using a planar point cloud distribution uniformity algorithm. Finally, the point cloud is restored to the same space to complete the contour extraction of the point cloud. The accuracy of the contour extraction method was verified by conducting point cloud feature extraction tests using standard components. Compared with conventional feature extraction, the method provides targeted local feature extraction for bars with a certain regularity of geometric configuration, reducing the time required for feature extraction and providing a brief database for the virtual assembly of steel joist beams.