INFLUENCE OF WELDING ON THE CRASH RESPONSE OF A REPAIRED CAR WITH UHSS STRUCTURAL MEMBERS University of Agder

Format:

Book

Conference/Event

Author/Creator:

Noorsumar, Gulshan, author.

Contributor:

Robbersmyr, Kjell

Rogovchenko, Svitlana

Vysochinskiy, Dmitry

Conference Name:

WCX SAE World Congress Experience (2020-04-21 : Detroit, Michigan, United States)

Language:

English

Physical Description:

1 online resource cm

Place of Publication:

Warrendale, PA SAE International 2020

Summary:

Noorsumar; Gulshan, Rogovchenko; Svitlana, Vysochinskiy; Dmitry, Robbersmyr; Kjell.G,University of Agder, NorwayKeywords: UHSS (Ultra-high strength steel); LS Dyna; Finite Element (FE); MIG welding; HAZ (Heat Affected Zone); Crashworthiness; Repaired CarThe word crashworthiness', [1] first used in the aerospace industry around the early 1950's provided a measure of the ability of the structure to protect its occupants in survivable crashes. In the automotive industry the term refers to the measure of vehicle's structural abilities to plastically deform and absorb sudden impact loads while maintaining enough survival space for the occupants.The goal of crashworthiness: Vehicle structures should be stiff in bending and torsion for proper ride and handling and should plastically deform in the event of a crash and absorb energy to prevent intrusions in the driver compartment. The structural integrity of cars comes at the cost of weight and fuel economy at times and engineers struggle to find the perfect balance between weight and crash performance. [2] The emergence of active and passive safety technologies has helped to resolve this issue and use of lightweight materials like ultra-high strength (UHSS) steels which have high yield strength is an increasing trend in the automotive industry. [3] The use of heat to repair damage to these parts or using it as a backing reinforcement for a sectioning joint is not recommended by the car makers. There is a need for research to understand if the crashworthiness of the vehicle is affected if these parts are welded after failure of the structural member. This study analyses the impact of welding structural members in a car like the A-pillar which use UHSS for reducing the weight of the car and improving the crashworthiness of the structure. Automakers generally recommend not to MIG weld these structural parts and they should be replaced as a whole part in case of a crash event. Sectioning of these members is also not recommended and use of the repair manual is mandatory in case of fracture of such parts. However, repair shops may not adhere to these instructions and use welding on these members which would modify their strength properties. The research conducted in this paper attempts to investigate the differences if any in the crash performance of a repaired car as opposed to baseline injury values for the car.The study uses a 2010 Toyota Yaris finite element (FE) model for conducting crash impact analysis and incorporating welding strategies and failure modes for the welded zone on the structural members. The result of the LS Dyna crash impact model like acceleration curves, intrusion measurements and deformation energy of the model is compared to crash test data published by NHTSA for the same model and make of the car. This will help detect the regions which are more affected by welding of the structural UHSS members and give directions to law making bodies to establish rules for preventing improperly repaired cars to be used by consumers. This study is novel because it's aim is to highlight the impact of heating on UHSS members in a car and determine the weakest zones in the structural members of the vehicle if they are welded after an impact. The study would be a starting point to address the issue of repair shops not following OEM repair manuals and leading to serious car crashes on repaired vehicles.References[1] Gonçalo, Sorger; Teemu, Sarikka; Pedro, Vilaça; Telmo, G. Santos "Effect of processing temperatures on the properties of a high-strength steel welded by FSW," Welding in the World (2018) 62:11731185[2] Furusako, Seiji; Miyazaki, Yasunobu; Uenishi, Akihiro "Improvement of Crashworthiness by Application of High-Strength Steel," Nippon Steel Technical Report No. 95 January 2007, UDC 669 . 14 . 018 . 292 - 415 : 539 . 537[3] Honda Body Repair News : August 2015

Notes:

Vendor supplied data

Publisher Number:

2020-01-0197

Access Restriction:

Restricted for use by site license