Automatic Geometric Recognition of Weld Beads for Supporting Virtual Prototyping and Cost Estimation of Welding

Author(s):  
Roberto Raffaeli ◽  
Marco Malatesta ◽  
Marco Mandolini ◽  
Michele Germani

Welding is widely used in industry for products made of joined sheet metal parts and beams. The virtual prototyping process of welds in standard CAD systems relies on functionalities to manually add weld beads to the assembly models. Weld beads can be in the form of symbolic annotations or 3D solid representations. The size of products in terms of number of parts and required weld beads makes this process cumbersome and time consuming. This paper presents a method to analyze CAD models of product assemblies in order to automatically identify possible welds among the parts using geometric recognition rules. Adjacent faces are detected and Boolean operators on planar loops are used to identify bead paths. Beads are then split in homogeneous portions based on the topology of the connected parts. The geometrical analysis of the connected parts also allows a bead to be characterized in terms of thickness, type, length and accessibility. Finally, the user is provided with functionalities to edit manufacturing properties or exclude unwanted welds. The approach is applied at the design stage to rapidly come to the definition of the welds. If integrated with a CAD tool, this can be used as input for an efficient detailing phase. Moreover, the paper presents an application for the cost estimation of the designed welded product. Weld beads are given a realization time, and hence a cost, based on their geometric size and employed welding technology. Some examples from the industry are presented to show benefits in terms of time savings and accuracy of the cost estimation process.

Author(s):  
Harshal Patwardhan ◽  
Karthik Ramani

Due to the ever-increasing competition in today’s global markets, the cost of the product is rapidly emerging as one of the most crucial factors in deciding the success of the product. Decisions made during the design stage affect as much as 70–80% of the final product cost. Hence, a manufacturing cost estimation tool that can be used by the designer concurrently during the design phase will be of maximum benefit. A literature study of the available cost estimation tools suggests that a majority of these tools are meant for use in the later stages of the product development lifecycle. In the early stages of a product lifecycle, the only information that is available to the designer is related to geometry and material. Hence, the cost estimation methods that have been developed with the intent of being used in the early stages of design make use of the geometric information available at that stage of the design. Most of the earlier models that use parametric cost estimation and features technology consider the design features in their implementation. However, such models fail to consider “manufacturing based features” such as cores and undercuts. These manufacturing based features are very important in deciding the manufacturability and the cost of the part. The Engineering Cost Advisory System (ECAS) is a knowledge-based system that presents cost advice to the designer at the design stage after considering various design parameters and user requirements. Some of these design parameters can be extracted via standard Application Programming Interfaces (APIs). Moreover, ECAS uses innovative techniques of geometric reasoning and the hybrid B-rep-voxel model approach to extract manufacturing feature-based geometric information directly from the CAD input. By considering the manufacturing based features along with the design parameters, the ECAS architecture is applicable to a much wider variety of manufacturing processes. The complexity of the part, which is derived from the geometric parameters (manufacturing based and design based) and other non-geometric user requirements (e.g. quantity, material), is used to estimate the manufacturing effort involved in process specific activities. The final cost is then estimated based on this manufacturing effort and considering the hourly rates of labor and other contextual resources as well as material rates.


Author(s):  
Oksana Veklych

The definition of economic damage from the deterioration/destruction of ecosystem services and analytical structuring of the economic loss from it were given for the first time. It was proposed and disclosed the logic-structural scheme that describes the algorithm of the sequence of actions and calculations for carrying out the cost estimation of damage from deterioration/destruction of ecosystem services in order to further substantiate the recommendations for additional filling of local budgets and attraction of targeted investments for implementation of projects aimed at conservation and restoration ecosystems.


2021 ◽  
Vol 11 (1) ◽  
pp. 28-33
Author(s):  
O. Kurasova ◽  
◽  
V. Marcinkevičius ◽  
V. Medvedev ◽  
B. Mikulskienė

Accurate cost estimation at the early stage of a construction project is a key factor in the success of most projects. Many difficulties arise when estimating the cost during the early design stage in customized furniture manufacturing. It is important to estimate the product cost in the earlier manufacturing phase. The cost estimation is related to the prediction of the cost, which commonly includes calculation of the materials, labor, sales, overhead, and other costs. Historical data of the previously manufactured products can be used in the cost estimation process of the new products. In this paper, we propose an early cost estimation approach, which is based on machine learning techniques. The experimental investigation based on the real customized furniture manufacturing data is performed, results are presented, and insights are given.


Author(s):  
N. SAMAL

The article is concerned with the problem of cost estimation for multifunctional construction projects on the stage of pre-investment feasibility study. For addressing issues such as the definition of capital investment unto the property assets the author considers the procedure of construction cost estimation on the base of the cost indicators of room function groups. On a research basis the author has developed the calculation methodology of the cost indicators of room function groups. Room function groups present the assembly of spatially connected facilities and communication passages which are focused on define operations functions accomplishment. There is the procedure of the application of room function groups costs for the definition of the investment volume in building construction in the phase of poorly detailed preliminary design.


2014 ◽  
Vol 41 (1) ◽  
pp. 65-73 ◽  
Author(s):  
Sangyong Kim ◽  
Jae Heon Shim

In this paper, we propose a hybrid case-based reasoning (CBR) system for predicting the construction cost of high-rise buildings at the preliminary design stage. First, the extracted cost factors (CFs) of a high-rise building were shown to significantly improve the cost estimation system’s performance. For developing a CBR system, a hybrid approach that combines CBR with genetic algorithms (GAs) for cost estimation was adopted. Genetic algorithms were used for optimized weight generation and applied to real project cases. Additionally, this paper proposes the identification of an alternative similarity score measurement formula. The proposed formula evaluates the contrast between the alternative case matching approach and the classical formula in a scenario involving the use of cost factors describing a case. The results indicate that the proposed GA-based CBR system can consistently reduce errors and potentially be useful to owners and contractors in the early financial planning stage. Accordingly, it is expected that the developed CBR system would provide decision-makers with accurate cost information to assess and compare multiple alternatives for obtaining the optimal solution and controlling the cost.


2020 ◽  
Vol 30 (3) ◽  
pp. 48-67
Author(s):  
Michał Juszczyk

Abstract Cost estimation, as one of the key processes in construction projects, provides the basis for a number of project-related decisions. This paper presents some results of studies on the application of artificial intelligence and machine learning in cost estimation. The research developed three original models based either on ensembles of neural networks or on support vector machines for the cost prediction of the floor structural frames of buildings. According to the criteria of general metrics (RMSE, MAPE), the three models demonstrate similar predictive performance. MAPE values computed for the training and testing of the three developed models range between 5% and 6%. The accuracy of cost predictions given by the three developed models is acceptable for the cost estimates of the floor structural frames of buildings in the early design stage of the construction project. Analysis of error distribution revealed a degree of superiority for the model based on support vector machines.


2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Abdulwahed Fazeli ◽  
Mohammad Saleh Dashti ◽  
Farzad Jalaei ◽  
Mostafa Khanzadi

PurposeAnalyzing different scenarios at the design stage of construction projects has always been a challenging task. One of the main parameters that helps owners in making better decisions in designing their buildings is to look after the cost perspective on different design scenarios. Thus, this study aims to propose a semi-automated BIM-based cost estimation approach that enables practitioners to estimate the cost of projects based on different design scenarios by an accurate and agile system.Design/methodology/approachThis study proposes an integrated framework, through which the cost estimation standard of Iran (FehrestBaha) is linked to the materials quantity take-offs (QTO) from BIM models. The performance of the system is based on connecting the classification standards of UniFormat and MasterFormat to the cost estimation standard of FehrestBaha. A BIM-based extension in the Revit environment is developed to automate the cost estimation process.FindingsTo evaluate the efficiency of the proposed approach in cost estimation, it is implemented to estimate the cost of the architectural discipline in a real construction project. The results indicate that the proposed BIM-based approach estimated the cost of the architectural discipline with an acceptable level of accuracy.Practical implicationsThe proposed approach could be used by practitioners to have an agile and accurate BIM-based cost estimation of different scenarios during design process. The semi-automated system considerably reduces the time of cost estimation in comparison to the traditional manual approaches, particularly in complex structures. Owners are able to easily trace changes in project cost according to any changes in components and materials of the BIM model. Furthermore, the proposed approach provides a practical roadmap for BIM-based cost estimation based on cost estimation standards in different countries.Originality/valueUnlike the traditional manual cost estimation approaches, the proposed BIM-based approach is not highly dependent on the knowledge of experienced estimators, which therefore facilitates its implementation. Furthermore, automating both QTO process and the required calculations in this approach increases the accuracy of cost estimation while decreasing the probability of human errors or omission occurrence.


2021 ◽  
Vol 1 ◽  
pp. 131-140
Author(s):  
Federica Cappelletti ◽  
Marta Rossi ◽  
Michele Germani ◽  
Mohammad Shadman Hanif

AbstractDe-manufacturing and re-manufacturing are fundamental technical solutions to efficiently recover value from post-use products. Disassembly in one of the most complex activities in de-manufacturing because i) the more manual it is the higher is its cost, ii) disassembly times are variable due to uncertainty of conditions of products reaching their EoL, and iii) because it is necessary to know which components to disassemble to balance the cost of disassembly. The paper proposes a methodology that finds ways of applications: it can be applied at the design stage to detect space for product design improvements, and it also represents a baseline from organizations approaching de-manufacturing for the first time. The methodology consists of four main steps, in which firstly targets components are identified, according to their environmental impact; secondly their disassembly sequence is qualitatively evaluated, and successively it is quantitatively determined via disassembly times, predicting also the status of the component at their End of Life. The aim of the methodology is reached at the fourth phase when alternative, eco-friendlier End of Life strategies are proposed, verified, and chosen.


1983 ◽  
Vol 31 (1_suppl) ◽  
pp. 60-76
Author(s):  
Patricia A. Morgan

Patricia Morgan's paper describes what happens when the state intervenes in the social problem of wife-battering. Her analysis refers to the United States, but there are clear implications for other countries, including Britain. The author argues that the state, through its social problem apparatus, manages the image of the problem by a process of bureaucratization, professionalization and individualization. This serves to narrow the definition of the problem, and to depoliticize it by removing it from its class context and viewing it in terms of individual pathology rather than structure. Thus refuges were initially run by small feminist collectives which had a dual objective of providing a service and promoting among the women an understanding of their structural position in society. The need for funds forced the groups to turn to the state for financial aid. This was given, but at the cost to the refuges of losing their political aims. Many refuges became larger, much more service-orientated and more diversified in providing therapy for the batterers and dealing with other problems such as alcoholism and drug abuse. This transformed not only the refuges but also the image of the problem of wife-battering.


2021 ◽  
Vol 11 (16) ◽  
pp. 7246
Author(s):  
Julius Moritz Berges ◽  
Georg Jacobs ◽  
Sebastian Stein ◽  
Jonathan Sprehe

Locally load-optimized fiber-based composites, the so-called tailored textiles (TT), offer the potential to reduce weight and cost compared to conventional fiber-reinforced plastics (FRP). However, the design of TT has a higher complexity compared to FRP. Current approaches, focusing on solving this complexity for multiple objectives (cost, weight, stiffness), require great effort and calculation time, which makes them unsuitable for serial applications. Therefore, in this paper, an approach for the efficient creation of simplified TT concept designs is presented. By combining simplified models for structural design and cost estimation, the most promising concepts, regarding the cost, weight, and stiffness of TT parts, can be identified. By performing a parameter study, the cost, weight, and stiffness optima of a sample part compared to a conventional FRP component can be determined. The cost and weight were reduced by 30% for the same stiffness. Applying this approach at an early stage of product development reduces the initial complexity of the subsequent detailed engineering design, e.g., by applying methods from the state of the art.


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