Industrial Welding Research Articles

Situational Awareness Oriented Interfaces on Human-Robot Interaction for Industrial Welding Processes

Safety, efficiency and effectiveness are important characteristics for human-robot interaction in a factory. So, workers and operators are exposed to challenges of interacting with these systems, in particular with welding robots. Considering the complexity of the industrial context and of the welding process itself, an important factor for the operator is "to understand what is happening" or to obtain situational awareness (SA). The SA increases decision-making capacity, reduces errors, and adds features to improve the human-robot interface (HRI). In order to integrate SA into interfaces for human-robot interaction, this work proposes the mapping of important aspects of SA for the welding process, based on a literature review and a case study to identify SA on interfaces for HRI. Finally, comments which aspects should be included in situational awareness oriented interfaces in order to provide more intelligent interfaces.

Optimize the Feed Rate and Determine the Joints Torque for Industrial Welding Robot TA 1400 Based on Kinematics and Dynamics Modeling

Optimize the Feed Rate and Determine the Joints Torque for Industrial Welding Robot TA 1400 Based on Kinematics and Dynamics Modeling

The Similar and Dissimilar TIG Welding of 316L and 321 Austenitic Stainless Steels

Being one the modern high quality industrial welding process especially for stainless steels and titanium alloys. TIG welding process has been has been researched for decades in order to define its parameters such as welding speed, current and arc length to improve the weld penetration. Hence it is a popular technique for joining thin materials - the thickness of the work piece is in general restricted to less than 6 mm- in manufacturing industries. In this study, AISI 321 and 316L stainless steel sheets of 4 mm of thickness were used as welding metals. Thus, AISI 321 welding metal couples, AISI 316L welding metal couples and AISI 321 and 316L welding metal couples were selected to ensure a combination of similar and dissimilar metals. The filler metal rod was made of 316L SS. The specimens were cut in dimensions of 150 x 30 x 4 mm as using an abrasive cutter, then the V weld butt joint configuration with single groove of 37.5o ± 2.5o groove angle by a lathe machine. The welding current was 200 A and TIG welding process was performed manually in single under argon shielding gas atmosphere. After TIG welding process, the separate metallographic preparations, then microscopic and macroscopic examinations of the specimens, also hardness measurements of specimens were made. The rest of them was shaped for tensile strength measurement using Instron Universal Testing Machine. The hardness of the specimens were observed being altered in the range of 145-151 HRV(average) and their tensile strength values in the scale of 345-400 MPa (average).

Dissimilar Lap Joint of Al6063 – AZ91 Mg Alloy by Friction Stir Welding

Developing dissimilar weld joints is still a technically challenging task in the welding industry. Several routes have been proposed to achieve defect free weld joints of dissimilar metals and alloys. Friction stir welding is one such promising route that completely eliminates melting of the base materials and facilitates to join the metals within the solid state. In the current work, Al6063 and AZ91 Mg alloy dissimilar lap joint was successfully done by friction stir welding. The joint between the base materials was formed due to the metallurgical bonding and mechanical mixing of the materials. Furthermore, from the X-Ray diffraction studies, development of a few intermetallics has been observed at the interface of the weld joint. From the microhardness measurements done across the weld joint, higher variations were observed within the weld zone due to the grain refinement and presence of intermetallics. The present work successfully demonstrates lap joint formation between Al and Mg dissimilar alloys by friction stir welding.

A structured light vision sensor for on-line weld bead measurement and weld quality inspection

Weld bead measurement and weld quality inspection are important parts in industrial welding. In this paper, a structured light vision sensor is developed to achieve on-line weld bead measurement and weld quality inspection. Firstly, a structured light vision sensor with a narrow-band optical filter is developed to reduce welding noises such as arc lights and splashes. Secondly, the weld bead type identification algorithm including image pre-processing, baseline extraction, and weld bead classification is proposed to classify filling weld bead and capping weld bead. Thirdly, feature extraction algorithms of filling weld bead and capping weld bead are presented to obtain corresponding feature points. Combining the image coordinates of feature points with structured light vision model, the weld bead size could be obtained and the weld quality could be evaluated. Finally, many weld bead measurement and weld quality inspection experiments are conducted. Experimental results demonstrate that the developed structured light vision sensor and proposed methods could achieve satisfactory performance for weld quality inspection.

Controlling martensite and pearlite formation with cooling rate and temperature control in rotary friction welding

A major limitation in industrial welding is the undesirable microstructures that form due to high peak temperatures and cooling rates. In particular, martensite and other brittle microstructures often form in steels during rotary friction welding (FW). In order to address this, cooling rate and temperature control is developed for FW. Limits of achievable FW cooling rates are primarily determined by thermal and geometric properties such as thermal diffusivity and length. A controller limits interface temperatures during a weld preheat, changing the thermal profile and slowing post-weld cooling.This method is demonstrated in 1045 steel. Cooling simulations, TTT diagrams, microhardness line scans, and scanning electron microscopy are used for analysis. Without temperature and cooling rate control, martensite readily forms after a weld. With temperature and cooling rate control, martensitic transformations are completely avoided and a pearlitic microstructure is developed. Temperature and cooling rate control is a viable tool in designing post-weld microstructures within achievable cooling rate limitations.

Application of MIG and TIG Welding in Automobile Industry

Emission and weight reduction have been identified over the years by the automobile industries as the most efficient ways to maintain fuel economy and to meet the demand of the government agencies on global warming. These challenges of reducing emission and weight are even being compounded with consumers taste for luxury features which adds to the weight of the traditional vehicle designs. To meet these demands, alloys such are Aluminium Alloys, Magnesium Alloys and Titanium Alloys have been identified as the suitable materials to replace conventional steel structures due to their superior properties such as high strength-to-weight ratio, high tensile strength and high-temperature performance. With the identification of suitable materials to replace the traditional materials, the welding of alloy materials remains a challenge faced by vehicle manufacturers. Although electron beam welding, ultrasonic welding and friction stir welding have proven to give quality weld joints of alloys used in automobile fabrication, their application is limited by the high cost of equipment, need for vacuum environment in electron beam welding, size and shape of base metals. Laser welding with its reduced heat affected zone (HAZ), good seam appearance and deep penetration has widely been applied in an automobile. However, it is not with its own shortcomings such as poor gap bridging capability, difficulty in welding reflective materials and high cost. Arc welding with its low cost compared to other welding techniques and high energy efficiency, therefore, remains a useful welding process in an automobile. In this paper, a review of the various investigations by researchers on MIG and TIG welding of alloys used in the automobile have been documented.

Strategic entrepreneurship, competitive advantage, and SMEs\u2019 performance in the welding industry in Tanzania

This study aimed at obtaining empirical evidence regarding the influence of strategic entrepreneurship on SMEs’ performance under the mediation of competitive advantage in the welding industry in Tanzania. Guided by the resource-based theory, this study adopted learning orientation, strategic resource management, and entrepreneurial orientation as strategic entrepreneurship components. Survey method with cross-sectional design was used to collect data from 300 owners-managers of welding industry SMEs located in Dar es Salaam, Morogoro, and Mbeya urban centers. Structural equation modelling technique was used to develop measurement and structural models. Findings suggest that learning orientation influences entrepreneurial orientation which influences strategic resource management to create competitive advantage that promotes SMEs’ performance. Findings of this study imply that the resource-based theory holds a better chance to describe the influence of strategic entrepreneurship components on SMEs’ performance under the mediation of competitive advantage than the individual resource-based view and knowledge-based view. It has been empirically demonstrated that knowledge is a unique resource that enables the acquisition of other resources and strategies. SMEs are urged to embrace learning orientation to create competitive advantage that leads to superior performance. The study has empirically verified that learning orientation, strategic resource management, and entrepreneurial orientation constructs adopted from entrepreneurship and strategic management literature are components of strategic entrepreneurship. Inclusion of strategic entrepreneurship components, competitive advantage, and SMEs’ performance with their composite measures in a single model distinguishes this study from past studies.

Characteristics of fume sedimentation in the working zone during arc welding with covered electrodes

In order to develop effective protection measures and reduce the number of diseases in the welding industry, a detailed study of the mechanism of propagation of welding fumes in the working zone is necessary. The present work investigates the characteristics of fume sedimentation in the working zone during arc welding with various covered industrial electrodes. The influence of covering type (rutile, basic, acid, and rutile-cellulose) on the quantity (number of particles) of РМ0.3…PM10 fractions in fumes is shown. Data on the absolute quantitative prevalence of particles of the smallest measured PM0.3 fraction (PM0.3/PM10 ≫ 75–90%) were obtained. Based on regression analysis, the sedimentation processes of welding fumes were modeled. The shortest forecast period of particles sedimentation is forecast for acid covered electrodes (53 min.), the maximum – for basic covered ones (150 min.). The maximum predicted distance of fumes distribution in space is expected for rutile-cellulose covered electrodes (16 m), the smallest – for rutile covered ones (6 m). The different types of electrodes for arc welding were ranked according to the degree of negative impact of exposure to fumes depending on the duration of their fume emission rate in the air and the propagation distance in the working zone.

Spatial Changes in Work Capacity for Occupations Vulnerable to Heat Stress: Potential Regional Impacts From Global Climate Change.

BackgroundAs the impact of climate change intensifies, exposure to heat stress will grow, leading to a loss of work capacity for vulnerable occupations and affecting individual labor decisions. This study estimates the future work capacity under the Representative Concentration Pathways 8.5 scenario and discusses its regional impacts on the occupational structure in the Republic of Korea.MethodsThe data utilized for this study constitute the local wet bulb globe temperature from the Korea Meteorological Administration and information from the Korean Working Condition Survey from the Occupational Safety and Health Research Institute of Korea. Using these data, we classify the occupations vulnerable to heat stress and estimate future changes in work capacity at the local scale, considering the occupational structure. We then identify the spatial cluster of diminishing work capacity using exploratory spatial data analysis.ResultsOur findings indicate that 52 occupations are at risk of heat stress, including machine operators and elementary laborers working in the construction, welding, metal, and mining industries. Moreover, spatial clusters with diminished work capacity appear in southwest Korea.ConclusionAlthough previous studies investigated the work capacity associated with heat stress in terms of climatic impact, this study quantifies the local impacts due to the global risk of climate change. The results suggest the need for mainstreaming an adaptation policy related to work capacity in regional development strategies.

Occupational competence needs analysis of welder on medium-scaled car body industries in Indonesia

The purposes of this research are 1) Identify the duties and 2) tasks of welders in medium-scale welding industries. This research uses a descriptive qualitative method. The research objects are 4 welders and 3 supervisors/chief productions from two medium-scale car body industries in Magelang, Indonesia. The data collection techniques used are documentation, observation, and interview. The data analysis techniques used are descriptive analysis and DACUM research chart which are validated by an expert’s judgment. This research manages to identify (1) six kinds of duties (plan the job, machinery and equipment preparation, material welding, inspect welding results, fix welding results, maintain machinery and equipment) and (2) seventeen kind of tasks that are executed by welders in medium-scale car body welding industries, twenty three knowledge and skills, nine working attitudes that should be owned by a welder, and at least nineteen kind of machines and supporting equipment in which the operation should be mastered by a welder in medium-scale welding industries.

Approximated analytical approach for temperature calculation in pulsed arc welding

In the modern welding industry, numerical modeling and simulation has become an invaluable tool in order to set up or tune new welding processes. For this purpose, the temperature distribution in a work piece can be modeled by a variety of different heat source models and numerical methods, including finite elements, volumes or differences. Arc welding applications usually employ pulsed power sources to increase efficiency and precision, which, by having to choose finer time stepping, increases the numerical expenses required in the simulations. Instead of the classical methods, in this contribution a Green’s function approach and the classical Goldak double-ellipsoidal heat source is used, getting an approximate analytical solution for the temperature field for a pulsed arc welding process, which is computationally efficient to evaluate and thus highly applicable. We derive an explicit equation for the temperature distribution, where only the time integration has to be solved approximately, run numerical tests and compare the results with FEM calculations.

Kinematics Simulation of Welding Manipulator Based on V-REPPRO EDU

As the primary tool in modern industrial welding, 6 DOF manipulator robots can weld in all positions. In this context, Danevit-Hartenberg parameters were developed to simplify kinematics equations for manipulator equations. Inverse kinematics is obtained based on the algebraic method. Simulation of kinematics manipulators based on V-REP PRO EDU is present. Kinematics simulations produce processing motion and relevant kinematics curves. The simulation results and kinematic equations of robotic manipulators are compared, showing that valid kinematic equations and weld trajectories can be passed by the end-effector successfully.

RELATIONSHIP CHARACTERISTICS OF WELDING WORKERS ON VISUAL LOANS IN THE WELDING INDUSTRY, PONTIANAK CITY

Vision (visual acuity) is a measure of how far the details of an object can caught by the eye so that the vision can be called an important eye physiology. Preliminary observations to 10 welding workers showed that 10 workers or 100% experience visual complaints with VFI more than 0.4 and many workers who complain of a sharp decrease in vision. This research is analytic observation research with cross sectional method. In this study the population was 91 respondents with Purposive Sampling sampling method so that the total sample was 74 respondents. Chi-Square test results on the discipline variable of PPE use obtained p - value (0.001) PR= 283.500( CI 95%= 30.060-2673.699) , length of work obtained p - value (0.001) PR=24.600 ( CI 95%= 6.961-86.935) , length of exposure obtained p - value (0.001) PR=30.000 ( CI 95%= 7.491-120.138) , exposure distance obtained p - value (0.001) PR=24.667 ( CI 95%= 6.824-89.157) , and daily habits obtained p - value (0.001) PR=23.611 ( CI 95%= 6.021-92.591) on sharpness vision so that it can be concluded that all variables have a significant relationship to sharp vision (vision ). Advive to the Manpower Office to make policies related to occupational safety and health for welding, fostering,and supervising workers in promoting and preventing efforts to prevent occupational diseases, especially those related to providing information that is expected to provide understanding to owners and welding workers on how to conduct safe welding and conduct periodic monitoring of occupational safety and health conditions to the welding industry and provide guarantees of safety to workrs so as to avoid occupational diseases. Keywords: Sharp Vision (Vision), Characteristics of Welding Workers, Welding Industry

Optimal trajectory generation of an industrial welding robot with kinematic and dynamic constraints

PurposeThis paper aims to present an optimal trajectory planning for industrial MOTOMAN MA1440A gas metal arc welding system. A new and efficient evolutionary algorithm, enhanced multi-objective teaching learning-based optimization (EMOTLBO) method, i.e. TLBO with non-dominated sorting approach has been proposed to obtain the optimal joint trajectory for the defined weld seam path.Design/methodology/approachThe joint trajectory of the welding robot need to be computed in an optimal manner for proper torch orientation, smooth travel of the robot along the weld path and for achieving higher positional accuracy. This can be achieved by limiting the kinematic and dynamic variations of the robot joints like joint jerks, squared acceleration and torque induced in the joints while travel of the robot along the weld path. Also, the robot travel should be done within minimum possible time for maintaining productivity. This leads to a multi-objective optimization problem which needs to be solved for maintaining proper orientation of the robot end effector. EMOTLBO has been proposed to obtain the Pareto front consisting of optimal solutions. The fuzzy membership function has been used to obtain the optimal solution from the Pareto front with best trade-off between objectives.FindingsThe proposed method has been implanted in MATLAB R2017a for simulation results. The joint positions have been used to program the robot for performing welding operation along the weld seam. From the simulation and experimental results, it can be concluded that the proposed approach can be effectively used for optimal trajectory planning of MOTOMAN MA 1440 A arc welding robot system as a very smooth and uniform weld bead has been obtained with maximum weld quality.Originality/valueIn this paper, a novel approach for optimal trajectory planning welding arc robot has been performed. Though trajectory planning of industrial robots has been done before, it has not been done yet for welding robot. The objectives are formulated taking in consideration of requirement of welding process like minimization of joint jerks and torques induced during welding operation due to travel of robot with the effect of arc spatter, minimization of squared acceleration for maintaining constant joint velocity and finally minimization of total travel time for maintaining productivity.

Discussion on the welding performance of automatic welding of industrial robot and manual welding

Since the introduction of industrial robots and their widespread application in manufacturing, the production quality and efficiency of manufacturing have been affected their automated welding performance directly. In this paper the author provides a useful basis for improving welding quality and promoting production efficiency through the analysis of industrial robot automatic welding technology standards and welding performance.

Light-Weight Topological Optimization for Upper Arm of an Industrial Welding Robot

To reduce weight and improve overall performance of the industrial welding robot, light-weight design using the finite element method and structural topological optimization is presented in this paper. The work analyzed an upper arm of an industrial welding robot in the most unfavorable working condition, both under static and dynamic working situations, using ABAQUS and ADAMS software tools. Then the Tosca unit in ABAQUS was employed to accomplish the structural topological optimization, in order to reduce weight and improve the natural frequencies under the situation of low orders. The analyses results showed that the actual weight had been reduced to 17.9%, and the natural frequencies in low orders had increased. The maximum Mises stress, tensile stress, and elastic displacement of the gyration center had decreased. Lastly, an actual product was produced according to the model obtained from preceding analyses. The experiments of the repeatability tests showed that the overall performance of the optimized upper arm had been improved when compared to the original one. This research can present references and foundations for the kinetic analyses under the static and dynamic working conditions, and structural topological optimization designs for relative industrial welding robots.

Orbital TIG Welding of Titanium Tubes with Perforated Bottom Made of Titanium-Clad Steel

Abstract The article presents problems accompanying the industrial TIG welding (142) of a heat exchanger perforated bottom made of steel clad with titanium B265 grade 1 with tubes made of titanium B338 grade 2. Research-related tests involved the making of test plates containing simulated imperfections formed during orbital welding. The above-named imperfections resulted from insufficient gas shielding during the welding process, the improper positioning of the tungsten electrode (excessively large or overly small circumference, around which the orbital welding process was performed), an excessive electrode travel rate being the consequence of an improperly set welding programme as well as excessively high welding current. Initial tests enabled the development of the orbital TIG welding of titanium tubes with the perforated bottom made of titanium-clad steel, satisfying acceptance criteria applied during commissioning.

Laser Welding in Different Spatial Positions of T-joints of Austenitic Steel

It has been selected the most industry perspective laser welding technological implementations of the welded T-joints made of fine-sheeted heat resisting steel AISI 321 by identifying the influence of technological parameters on formation quality, level of mechanical properties and structural peculiarities of the welded T-joints obtained by laser welding in different spatial positions.

Statistical Analysis of Korean Welding Industry (IV)

구 분 분류코드 산 업용접기C28909301 아크 용접기C28909302 저항 용접기C28909309 기타 전기용접기C29199101 가스 용접 및 절단기C29199102 기타 용접기용접재료 C25999201 용접봉주력산업 C262전자부품, 영상, 음향 및 통신장비 제조업C30 자동차 및 트레일러 제조업C311 선박 및 보트 건조업기타제조업 C263, 2918 컴퓨터 및 사무용 기기 제조업C28기타 전기기계 및 전기변환장치 제조업C27 의료, 정밀, 광학기기 및 시계제조업C312 철도장비 제조업C313 항공기, 우주선 및 부품제조업