A model was developed to facilitate secondary tailgate support selection based on analysis of a data base of over 100 case studies compiled from two different surveys of operating longwall coal mines in the United States. The ALPS (Analysis of Long wall Pillar Stability) program was used to determine adequacy of pillar design for the successful longwall case histories. A relationship was developed between the secondary support density necessary to maintain a stable tailgate entry during mining and the CMRR (Coal Mine Roof Rating). This relationship defines the lower bound of secondary support density currently used in longwall mines. The model used only successful tailgate case history data with adequate ALPS SF according to the CMRR for each case. This model facilitates mine design by predicting secondary support density required for a tailgate entry depending on the ALPS SF and CMRR, which can result in significant economic benefits. / Master of Science

Abstract This report focuses on the creation of a software to calculate handling forces of bonnet and tailgate. The handling force is the force required by a user to open or close a tailgate. It is a bachelor thesis conducted for Karlstad’s university. The work is conducted at CEVT in Gothenburg, the software will be used to improve workflow in early design phases. The resulting software from this project is easy to use and shows good resemblance to the reference values, which is old calculations done by a manufacturer. Comparing to manufacturer calculation the software shows only small deviations in results. The software is deemed to be an asset in the development work at CEVT. The software is also easy to use and have been tested by employees, whom could operate the software easily without instructions. It is based on regular equilibrium equations and the software structure is logical and easy to follow, to make it simple to maintain and develop the software if the need would arise. The finished software calculates single pivot hinges and four bar mechanism-based hinges equipped with gas springs. It also has the possibility to work with tailgate and bonnet simultaneously to keep one project in one file. The work has focused on, creating the software, user interfaces and kinematics/kinetics of different types of hinges, with support from both literature and reports. This led to a software built in Microsoft Excel, which was chosen due to its standard features for graphical display of data. Building the software in Excel also makes it accessible to all employees who wishes to use it. The conclusion is that the software could in extension lead to higher quality on finished products by allowing more tested configurations and continuous changes during the design process. / Sammanfattning Denna rapport behandlar utveckling av mjukvara för att beräkna hanteringskrafter. Hanteringskrafter är de krafter som krävs av användaren för att operera motorhuv och baklucka. Projektet är genomfört som ett examensarbete på Karlstads universitet. Arbetet utförs hos CEVT i Göteborg, där resultatet av arbetet kommer användas för att förbättra designprocessen i tidiga stadier. Den slutgiltiga mjukvaran är enkel att använda och uppvisar resultat som ligger nära referensvärdena, som är gamla beräkningar gjorda av en tillverkare. Endast mindre avvikelser finns mellan beräkningarna. Mjukvaran bedöms vara en tillgång I designarbetet hos CEVT. Mjukvaran är också enkel att använda och har testats av de anställda som kunde använda mjukvaran utan instruktioner. Den är baserad på vanliga jämnviktsekvationer, medan strukturen i programmet är enkel att följa och förstå, detta för att göra det enkelt att underhålla och utveckla om behovet uppstår. Den slutgiltiga mjukvaran beräknar vanliga gångjärn och gångjärn baserade på fyrledsmekanismer utrustade med gasfjädrar. Mjukvaran ger också möjlighet att jobba med både motorhuv och baklucka samtidigt för att kunna hålla ett projekt inom en fil. Arbetets fokus har legat på att, skapa mjukvaran, användargränssnitt och kinematik/kinetik hos olika typer av gångjärn, med stöd inom både litteratur och rapporter. Detta resulterade i en mjukvara byggd i Microsoft Excel, som valdes på grund av dess funktioner för att grafiskt representera data. Att skapa mjukvaran i Excel innebar också att alla på företaget kan använda mjukvaran. Slutsatsen är att mjukvaran skapar en möjlighet att höja kvalitén på färdiga produkter genom att möjliggöra fler testade konfigurationer och kontinuerliga förändringar under designprocessen.

A nominal setup at Volvo Cars Corporation is the placement determination for two adjacent exterior parts on the car. To place the parts in optimal positions, nominal values for gaps and flushes are determined. When a nominal setup becomes more complex, VSA (Vehicle System Architect) is summoned. These appearing situations regard the involvement of several attributes and the need for a combination of vari- ous contributions. There are static, dynamic (overslam or dynamic movement) and thermal contributions that are combined into nominal values of gap and flush dis- tances. The determination process of a nominal setup contains both calculation for each contribution, as well as the combination method which takes place at the VSA meetings. This Master Thesis project consists of the development of an improved determination process for nominal setups. The current determination process has a low level of transparency within the differ- ent group’s methods. Another issue is the insecurity of the probability estimations made when combining the contributions. Therefore, the focus of the project was to infuse a greater understanding of the contribution derivations, and greater insight into the probability of the taken risks. To achieve that, the project was divided into three parts; mapping of the determination process, individual contribution improve- ments and finally, improvements to the combination method. In contemplation of improving a process, plenty of knowledge needs to be gathered, regarding methods, simulations and possibilities. This was executed by interviewing experts within spe- cific areas at the different groups at VCC. Development of the improvements was done by interviews and various studies. It was shown that the mapping of the determination process increased the trans- parency between the groups as it increased the understanding of individual groups’ work. Contribution improvements lead to more realistic load cases used for dimen- sioning. A performed overslam clinic, where closing velocity data of a tailgate were collected, lead to a greater statistical base for which load case should be used. For dynamic movement, another method is proposed that considers relative movement instead of applied accelerations. For the thermal contribution, the approach of ge- ographically gathered temperature data was proposed. The improved combination method generates combinations with regard to three input values instead of one, from each contribution, to create different combination scenarios. The probabilities of the scenario occurrences are estimated which gave VCC a greater understanding of what risks that are taken. Furthermore, the combination method also educates the VSA meeting attendees by exhibiting the derivations and bases for each contri- bution.

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