Cost Affecting Factors Related to Fillet Joints

Fillet welds are by far the most frequent arc welding joint type in the fabrication industry with about 80% of all arc welded joints worldwide. Alt-hough the joint is well established, there are many aspects to consider when pro-ducing an ideal weld. This paper reveals and connects several problematic issues related to the joint type and the difficulties to fabricate a weld with correct strength, cost, and quality. Excessive welding of fillet welds is common, resulting in increased fabrication cost. There could be several causes for this; the designers do not customize the weld demand for the different stress levels and the production adds even more to handle the variation in the process. Previous studies shows that the combination of these factors can result in 100% extra weld metal, compared to what should be needed to fulfil the strength demands. Inspections are another contributor to excess welding. The capability of the weld size measurement method used by welders and inspectors is unsatisfactory. Measurement system analyses show that the scatter from the measurement system itself is in the same range as the scatter from the process. A critical summary of the current state-of-the-art is that fillet welds are hard to specify and fabricate with the right size, that the measuring method is incapable and the connection between size and strength is weak

Impact of Gaps on Resource Efficiency in Heavy Welding Industry.

This paper describes a study investigating the current situation concerning plate gaps in welding operations at a company producing welded products. A varying gap between the plates has been identified as a root cause for quality issues and unnecessary costly welds, hence affecting resource efficiency. The result showed signs of vast variations of gaps, both concerning the size of gaps and presence of an extra weld. The investigation indicates a large potential, possible to achieve without heavy investments

The Right Evaluation Method - an Enabler for Process Improvement

This paper aims at describing the procedure where an alternative evaluation process was developed to support the improvement of both welding and weld quality evaluation. Welded structures are important when striving for reduced fuel consumption due to vehicle weight. Hence good control of the fabrication process is critical to keep welding performance on target, avoiding waste in terms of added weight and overproduction. The resulting distribution of weld weight has shown to be an important control parameter in the sense of keeping cost down. To identify the causes for deviations between actual and theoretical weld weight, information about the weld was needed. The currently used evaluation method showed not to be capable of giving the information needed. It was necessary to know the throat size as well as weld geometry. The current evaluation method introduced more variation due to the measurement than the actual fabrication process itself, leading to drift of process target and overproduction. To fulfil the need of information, that different functions within the company had, a PULL-approach was used. The information need, information presentation and sequence were outlined for each information receiver individually. An alternative measurement method was developed and named WIA – Weld Impression Analysis. The method consists of two parts; creating the replica and analysing the shape in an image analysis program. The method was tested to see if it was capable of delivering accurate and precise measurements, satisfying repeatability and reproducibility requirements for this particular situation. A thorough measurement system analysis was carried out. The measurement system assigned 98.98% of the total variation to part-to-part variation corresponding to long-term process variation. The variation that stems from taking the impressions and preparing them was as well investigated, also showing satisfying results. Finally it was investigated if the impressions reflect the true shape of the welds accurately. The results showed a tendency of slightly higher cross sectional areas in the range of 0-3 %. This however indicated that the accuracy of the measurement system was sufficient for its purpose. The PULL-approach generated a sufficient method which enabled the possibility to perform process improvement and gain large production cost savings

The Influence of Correct Transfer of Weld Information

ABSTRACT This study aims at identifying the causes for deviations between actual and theoretical weld weight. Previous performed studies have shown examples of up to 40% extra weld consumables used in some cases. One consequence is of course higher production cost but it can also give increased weight leading to higher fuel consumption and decreased payload. An interesting aspect is that generous margins on specific production measures dilute important feedback of process variation information preventing and prolonging structural root cause analysis. The causes for the observed deviations can heritage from several areas, both technical and within the information handling. The investigation shows that single components of the information structure and system, such as unsuitable demands as well as incapable evaluation methods, significantly influences the reliability of the entire manufacturing process. The common factor concerning when problems occur, seems to be the ability of correct information transfer between different functions in the organisation preventing the mismatch to appear in the interface. Suggestions for improving this situation include cross functional agreements as well as new measuring methods

Factory 4 Tomorrow Organization-Challenges and Enablers to Encourage Simultaneous Exploration and Exploitation

This paper identifies challenges and proposes enablers for simultaneous exploration and exploitation in Operations (the production part of a manufacturing company). It also contributes with an empirical example of organizing dual operating systems through behavioral ambidexterity during the digital transformation journey. The main challenges related to achieving simultaneous exploration and exploitation are communication, involved resources, innovation process, collaboration, and implementation. One of the proposed enablers is to develop a more supportive culture through awareness and competence development of managers about the competing cultures of exploration and exploitation. Further on, the diagnostic of opportunities model (the readiness and maturity evaluation model) is an overall enabler and can be used as a supportive dialogue tool to address several of the challenges identified. In addition to this, there also needs to be a strong focus on overall continuous communication and follow-up, especially of the proposed enablers, to support the overall change approach to reach strategic legitimacy in the organization

Barriers for industrial implementation of in-process monitoring of weld penetration for quality control

The research conducted sheds a light on the question why robust in-process monitoring and adaptive control are not fully implemented in the welding industry. In the research project FaRoMonitA, the possibilities to monitor the weld quality during welding have been investigated. Research conducted in this area has merely focused on technical issues investigated in a laboratory environment. To advance the research front and release some barriers related to industrial acceptance, the studies conducted in this paper have been both quantitative and qualitative in form of experiments combined with an interview study. The quality property weld penetration depth was chosen for in-process monitoring to evaluate the industrial relevance and applicability. A guaranteed weld penetration depth is critical for companies producing parts influenced by fatigue. The parts studied were fillet welds produced by gas metal arc welding. The experiments show that there is a relationship between final penetration depth and monitored arc voltage signals and images captured by CMOS vision and infrared cameras during welding. There are still technical issues to be solved to reach a robust solution. The interview study indicates that soft issues, like competence and financial aspects, are just as critical

How to succeed with Co-production : Experiences from industrial researchers

The aim of this handbook is to raise awareness of the differently organised systems when collaborations are to be set up between companies and universities. By presenting experiences from industrial researchers this handbook will be useful for persons that are going to work in a collaborative setting, regardless of whether they come from a company or a university.Innofactur

Sustainability with a Cost Perspective – Driving the Industry to Embrace Sustainable Thinking

Previous research has shown that sustainable improvements need incentives to carry them through. An assumption is that it may be easier to incorporatesustainable thinking in an organization if the organization understandswhich actions it is that are having a positive effect on sustainability andon tangible costs. This paper aims to highlight the synergy effects thatoccur in the intersection between production costs, performance and sustainableimprovements and to present a possible way of modelling theseeffects. The study has used three methods of analysis: literature review, aweb survey sent to representatives in the Swedish manufacturing industry,and economic simulations using a case study. The literature review and thesurvey are used to identify important costs and incentives for sustainableimprovements. The study is limited to the production shop floor level, incorporatingonly aspects directly affecting, and affected by manufacturingoperations.This paper takes a holistic approach to sustainability drivers, cost driversin industry, and economic simulations, creating an overall insight. Fromthe literature review and the survey, intersections between sustainabilitymeasures and cost drivers could be found in the areas of site-occupancyarea/floor space, resource consumption, and efficiency. Apart from lawsand regulations, economic aspects and management attention are perceivedas the most important drivers, but also obstacles for sustainability improvements.The study aims to support industry to embrace sustainable thinking,presenting a quantitative method to visualize the synergy effects of sustainabilityand measurable improvements from production development,using performance measurements when estimating manufacturing costs.The possibility to connect manufacturing cost with environmental impact,through use of performance parameters is demonstrated in a case study;where the significant environmental and economic impact of rejections isanalyzed for the machining of steel frame