Safety-shaped median barriers have long been employed to keep misguided vehicles on the roadway. In recent years there has been a growing national desire for more aesthetically pleasing roadside safety systems. Adding surface texture is one of the most popular ways to make a more aesthetically pleasing barrier. This practice of adding surface texture can potentially reduce the safety performance of the barrier. The purpose of this research was to develop guidelines for the aesthetic surface treatment of safety-shaped median barriers. Numerical simulation was utilized to develop these guidelines. This was done by first validating the vehicle model that was used in this research, which was the National Crash Analysis Center (NCAC) 2000P Detailed Pickup Truck model. The validity of the vehicle model could be determined by comparing the vehicle dynamics of the simulation to the actual crash test data for the smooth surfaced Single Slope and New Jersey Safety-Shaped barriers. Crash tests involving concrete median barriers most commonly fail crash testing criteria given by the National Cooperative Highway Research Program (NCHRP) Report 350 by excessive Occupant Compartment Deformation (OCD). OCD is excessive deformation of the occupant compartment that would cause severe harm to the occupant. Current simulation vehicle models do not give reliable direct measurement of OCD. To take the place of direct measurement, several parameters were measured to find the best surrogate measure of OCD. The internal energy of the floorboard in the NCAC 2000P Detailed Pickup Truck model gave the best correlation to OCD. By simulating several different past crash tests with passing and failing OCD, limits of internal energy in the floorboard could determine if a simulation had passing, marginal, or failing amounts of OCD. Using the surrogate measure of OCD a parametric study was then evaluated by NCHRP Report 350 standards. The parametric study of 29 simulations varied width and depth of recess between asperities for two different angles of asperities. Guidelines were determined for the 45? and 90? angles of asperities as a curve on depth vs. width of recess between asperities from the results of this parametric study.

Det här examensarbetet genomfördes sommaren 2017 på Autoliv Test Center i Vårgårda. Autoliv är världens ledande leverantör av säkerhetsutrustning och utvecklare av säkerhetssystem för fordonsindustrin. Autoliv genomför även krockprovning för kunder som vill genomföra tester av deras bilar före produktion. Vid krockprovning accelereras testfordonet av en krockprovningstrolley som kopplar samman fordonet med en vajer vilket drivs genom ett hydrauliskt framdrivningssystem. Trolleyn är en stålkonstruktion som är placerad i krockspåret vilket griper fast i stålvajern med ett klämsystem. Krockprovningsindustrin är i ständig utveckling med nya säkerhetssystem, hårdare regler och tuffare krav från myndigheter och fordonssäkerhetsorganisationer. Ett nyligen introducerat test kallat NHTSA Oblique 90km/h hade svårt att genomföras på grund av att klämmekanismen slirat vid genomförandet. Målet med examensarbetet har varit att ta fram en ny krockprovningstrolley som fungerar när den genomför NHTSA Oblique 90km/h. Arbetet har varit inriktat på att designa en trolley som fungerar under nuvarande förhållanden utan att göra inverkningar på krockbanan eller framdrivningssystemet. Fyra koncept har designats i 3D, utvärderas i en konceptmatris, diskuterats med erfaren personal och ett koncept valdes ut för fortsatt utveckling. Effekterna av den nya designen på komponenter har undersökts och justeringar genomfördes. En FEM-analys gjordes på det vinnande konceptet för att bedöma hållfastheten på trolleyn samt potentialen för viktoptimering. Resultat var en ny trolleyplatta, 20 cm längre och 10mm tunnare. Den ursprungliga plattans vikt bevarades och designen rekommenderades av personal på ATC. Trolleyn diskuterades och ytterligare rekommendationer gavs. / This thesis was performed in the summer of 2017 at Autoliv Test Center in Vårgårda. Autoliv is the world’s leading automotive safety supplier and developer of safety equipment for the vehicle industry. Autoliv also performs crash testing for customers wanting their concept cars tested before production. In crash testing, the vehicle is accelerated by a crash track trolley that connects the vehicle to a steel wire driven with a hydraulic propulsion system. The trolley is a steel construction positioned inside the crash track gripping the wire with a clamping mechanism. The crash testing industry is in constant development due to new safety systems, harder regulations and tougher requirements from governments and vehicle safety organizations. A recently introduced crash test called the NHTSA Oblique 90km/h had issues being performed due to slip between the clamping system and steel wire. The goal of this thesis has been to develop a new crash track trolley that does not malfunction during crash testing. The work has been aimed at designing a trolley that functions at current conditions without implications on the crash track or propulsion system. Four concepts have been designed in 3D, evaluated in a concept matrix, discussed with senior staff and one concept was chosen for further development. The effects of the new design on components have been investigated and adjustments were made. A FEM-analysis was done on the winning concept to look into the physical integrity of the new trolley as well as the potentials in weight optimization. The result was a new trolley plate, elongated by 20 cm and thinned by 10 mm. The same plate weight was preserved and the trolley design was recommended by senior staff at ATC. The trolley was discussed and further recommendations were given.

The purpose of this study is to develop and analyze the possibilities of implementing a new crash test method for child bike trailers based on StVZO §67 Explanation 19 Appendix 2 at Thule Test Center or use an alternative method. The study is based on the following three problem statements: can a new method based on StVZO §67 Explanation 19 Appendix 2 replace TÜV and RISE test methods? Is it possible to implement a new test method in Thule Crash Lab using the acceleration sled track or using a different approach? How can crash testing contribute to optimizing the development of child bike trailers? This study began with background information and the problem description of Thule’s lack of test method and their need for a new alternative. The theorical background provides information about testing for product development. It also provides information about StVZO §67 Explanation 19 Appendix 2 which will be the basis for the study and the previous test methods Thule has used, which were RISE and TÜV.  Observations, analyzes and an interview from the previous test methods established the foundation for the concept study which included brainstorming sessions to generate concepts for the new test method. The concepts consisted both of methods with and without the acceleration sled track. Several workshops served as concept selections which filtered out concepts that exceeded limitations of the facilities at Thule Test Center. The concepts that could not fulfill the requirements from StVZO §67 Explanation 19 Appendix 2 was also filtered out.  To find out if the acceleration sled could be used as a test method, different tests were involved which included evaluation of test impulses and crash tests with handmade fixtures for the child bike trailer. This was carried out to ensure that the crash sled could operate under the variables that was calculated in preparation for the test and that the fixtures could handle the accelerations.  The study also included discussions and conclusions with suggestions for modifications to the concepts that could not be directly implemented due to the limitations in Thule facilities. Some of the modifications were also taken up as suggestions for further research. The study also included comparison between internal and external testing. The comparison explained the importance for Thule to have an internal test method and generally an alternative for crash testing their child bike trailers. As presented in the study, crash testing is crucial for an optimized development of new child bike trailers to ensure safe, qualitative and durable child bike trailers. It is also crucial to stay competitive in the market. To validate stresses and forces subjected onto the construction of the final test method, static calculations were performed which gave an indication of what dimensions the beams for the construction could have. As discussed, dynamic calculations could have been done to achieve a more precise and accurate result.  The final test method is an example of what Thule could use for crash testing their child bike trailers with the requirements from StVZO §67 Explanation 19 Appendix 2. Design changes are possible if it were to be implemented and the new test method gives Thule an internally option.

23% of passenger vehicle occupant deaths in 2019 was side-impact collisions and is a ongoing problem that continues to take people’s lives (IIHS, 2021a). IIHS (Insurance Institute for Highway Safety) is an organization based in USA, which performs vehicle crash tests with the goal of making cars safer and reducing deaths and injuries. In 2023, a new, tougher side crash test will be introduced by IIHS in the USA to tackle those crashes and save lives. The goal for IIHS with their vehicle tests is to urge the car manufacturers to make safer vehicles. Manufacturers in the automotive industry knows that the customers are using the ratings as a guide before buying a vehicle, which forces them to adapt the vehicles to pass the tests and have a good rating. In early crash tests with the updated side crash test, a lot of vehicles from a selection of different manufacturers struggled to pass the test requirements and it seems like the new test requires change of component strength and design.  This is a master thesis project in Industrial Design Engineering with the focus on Product Design, at Luleå University of Technology (LTU), and has been performed on behalf of Gestamp HardTech at their R&D department in Luleå, Sweden. The early parts project focused on finding which car components has the largest influence of the crash result, where the components might need to be reinforced or having less strength.  To help simulating the side crash, full vehicle side-impact crash simulations were used in this project with a virtual reference FEM car made by Gestamp, GLAB G3 EV. This project has been using the CDIO-design process, which stands for Conceive, Design, Implement and Operate.  In the first phase, Conceive, simulations were made and the current IIHS side crash test was compared with the new IIHS test. The left-side side-impact beams was chosen as the components to trying to improve in the project. Creative methods in the Design-phase were generated ideas, which was 3D CAD modeled in CATIA V5 and tested with three-point bending simulations in LS-DYNA.  The three-point bending simulations were analyzed and the best performing designs were chosen, to later be simulated with full vehicle side-impact crash simulations in the Implement-phase. The results from these simulations were used to develop ten different concepts of combinations of left-front and left-rear side-impact beams and ten final full vehicle simulations were conducted and analyzed on factors such as door intrusion, component weight and more. From these concepts, the two final concepts were selected with the use of the Pugh Decision Matrix, and these two concepts had the highest rating score from this matrix. These two concepts, Final Concept and Alternative Concept, are the final results of the project. Each concept has a combination of a left-front side-impact beam and a left-rear side-impact beam. The two final concepts are reducing the side crash intrusion on the side-impact beams compared to the reference simulations conducted with the new IIHS side crash test. The Final Concept were the best concept in the results from the matrix and is reducing the total side crash intrusion on the left-side of the car by 161 mm compared to the reference simulations The reason why an Alternative Concept to the Final Concept was selected was because it has very different design and thickness compared to the Final Concept, and even though it only has 94 mm total side crash intrusion  reduction on the left-side of the car compared to the reference simulation, it was looked on a potential alternative to the Final Concept with further work and development applied to it. / 23% av dödsfallen i passagerarfordon under 2019 var sidokrockar och är ett pågående problem som fortsätter att ta människors liv (IIHS, 2021a). IIHS (Insurance Institute for Highway Safety) är en organisation som är baserad i USA som utför fordonskrocktester med målet att göra bilar säkrare och minska dödsfall och skador. 2023 kommer ett nytt, tuffare sidokrocktest att introduceras av IIHS i USA för att tackla dessa krascher med målet att rädda fler liv. Målet för IIHS med sina fordonstester är att uppmana biltillverkarna att göra säkrare fordon. Tillverkare inom fordonsindustrin vet att kunderna använder betygen som vägledning innan de köper ett fordon, vilket tvingar dem att anpassa bilarna för att klara testerna och få ett bra testbetyg. I tidiga krocktester med det uppdaterade IIHS sidokrocktestet hade många bilar från ett flertal biltillverkare för att klara testkraven och det verkar som om det nya testet kräver förändring av styrka och design i bilens komponenter. Detta är ett examensarbete i Civilingenjör Teknisk Design med inriktning på produkt design vid Luleå Tekniska Universitet (LTU), och har utförts på uppdrag av Gestamp HardTech vid deras FoU-avdelning i Luleå, Sverige. Början av projektet fokuserade på att hitta vilka bilkomponenter som har störst inverkan på krockresultatet, ta reda på var komponenterna kan behöva förstärkas eller ha mindre styrka. För att hjälpa till att simulera sidokrocken användes helbilssidokrocksimuleringar i detta projekt med hjälp av en virtuell FEM-bil tillverkad av Gestamp, GLAB G3 EV. Detta projekt har använt CDIO-designprocessen, som står för Conceive, Design, Implement och Operate. I den första fasen, Conceive, gjordes simuleringar och det nuvarande IIHS sidokrocktestet jämfördes med det nya IIHS testet. De två sidokrock-skydden på vänstra sidan av bilen valdes som komponenter att försöka förbättra i projektet. Kreativa metoder i Design-fasen genererade idéer, som 3D CAD modellerades i CATIA V5 och testades med trepunktsböjnings-simuleringar i LS-DYNA. Trepunktsböjningssimuleringarna analyserades och de bästa presterande designerna valdes ut, för att senare simuleras med helbilssidokrock-simuleringar i Implement-fasen. Resultaten från dessa simuleringar användes för att utveckla tio olika koncept av kombinationer av sidokrockskydd till vänster fram och vänster bak av bilen och tio slutliga helbilssidokrock-simuleringarna genomfördes och analyserades på faktorer som intryckningen i dörrarna, komponenternas vikt med mera. Från dessa koncept valdes de två slutliga koncepten ut med hjälp av Pughs beslutsmatris, och dessa två koncept hade det högsta betyget från denna matris. Dessa två koncept, Final Concept och Alternative Concept, är projektets slutresultat. Varje koncept har en kombination av ett sidokrockskydd på vänster-fram och ett sidokrockskydd på vänster-bak. De två slutgiltiga koncepten minskar dörrintrånget på sidokrockskydden jämfört med referenssimuleringarna som genomfördes med det nya IIHS sidokrock-testet. Final Concept var det bästa konceptet i resultaten från matrisen och minskar det totala sidokrockintrånget på bilens vänstra sida med 161 mm jämfört med referenssimuleringarna. Anledningen till att ett alternativt koncept till det slutgiltiga konceptet valdes var eftersom den har väldigt olika design och tjocklek jämfört med det slutliga konceptet, och även om den bara har 94 mm total reduktion av sidokrockintrång på vänster sida av bilen jämfört med referenssimuleringen, såg man detta koncept som ett potentiellt alternativ till Final Concept med fortsatt arbete och utveckling tillämpat på detta koncept.