Is the Body Repair Industry Ready for the Composite Onslaught?

Part 3 of Automotive IQ's Series on Lightweight Materials

In recent years progressive automotive manufacturers have heralded composites, in particular carbon fibre reinforced plastics (CFRP), as the answer to significant weight reduction demands.

Image credit: wot.motortrend.com

However, dealers and body repair shops face several daunting challenges when presented with an accident damaged vehicle:

• How to determine the extent of damage to CFRP structures?
• How do they decide whether to repair or replace the damaged structures?
• What is the appropriate repair method and material?

The correct evaluation and choice of repair procedure is critical: Not only for safety reasons but to also ensure the most cost-effective repair for the insurer who foots the bill and ultimately determines the premiums to be paid.

Unlike steel or aluminium, a damaged CFRP body part, whether structural or hang-on, may not exhibit the severity of the damage which could range from surface delamination to deep delamination and core damage. Correct diagnosis of the extent of the damage requires training and specialised equipment not currently available to most dealerships and repair shops.


Image credit: National composite Network (Ajay Kapadia)

Lamborghini’s solution to skills and equipment requirements

Recognizing that the extensive use of carbon fibre composites in the Aventador would make field repairs a challenge, Lamborghini collaborated with Boeing and the ACSL to develop a strategy for assessing the level of damage sustained by Aventador CFRP elements before providing specialized field support to customers.

Casper Steenbergen, head of repair at Lamborghini’s Advanced Composite Research Centre (ACRC), says, "We set up a complete strategy in order to determine whether to repair or replace pieces of a damaged car." The process is as follows:

• The Lamborghini dealership orrepair shop submits an initial damage report including a quick claim, via their Web-based portal.

• Experts at Lamborghini’s ACRC examine the information and try to determine the extent of the damage.

• If the damage is structural a technician from an external company specializing in non-destructive inspection (NDI) is sent to examine the vehicle for hidden damage in critical zones.

• The technician sends his findings to Sant’Agata where it’s examined alongside the original report, and if the ACRC’s multidisciplinary team determines that a critical chassis component has been damaged, one of its specially trained technicians is dispatched to repair the car.

• The automaker calls this elite group of four technicians its "flying doctors" and says they are on call 24/7/365 to travel to any location where an Aventador’s composite structure has been damaged.

• Because the vehicle combines several CFRP technologies, including prepreg and Resin Transfer Molding/braid on both Class A and non-Class A parts, the technician carries with him all the materials and equipment needed to repair the damage; including a hot bonder connected to two different heater blankets, each with its own controls, so that two different materials with two different curing cycles can be repaired at the same time.

• Depending on the extent of the damage, the repair might take between 1 and 14 days. Finally, when crosslinking is complete, a portable ultrasound unit is used to scan the part to ensure patch integrity.

Even though this strategy is cheaper than replacing a major chassis component or scrapping a car, it would be impractical and far too expensive to apply to high volume and less expensive vehicles.

The costs that could be incurred were well highlighted after the much publicised accident involving actor Rowan Atkinson's rare McLaren F1.

Following the 2011 incident in which the F1 was extensively damaged, it took more than a year and 900,000 pounds — to have the vehicle repaired.

According to Ben Stagg, specialty insurer with RK Harrison, the quality components (Referring primarily to the Carbon composite tub) used to make the F1 had a significant impact on the repair costs.

However, having launched the first high(er) volume small vehicle to make extensive use of CFRP and other composites, BMW contend that repair costs will actually decrease through the use of a composite structure on the i3.

BMW’s philosophy on reduced repair costs on composite structures

Manuel Sattig, the communications manager for BMW i explains: "If the car is involved in a minor accident, only the exterior plastic parts are damaged. These are easily replaced by clicking out the damaged parts and replacing them with new ones. In case of a higher impact the carbon fibre will possibly be damaged. However because carbon fibre does not deform, the damage is localised to a specific area. The damaged area can easily be removed using a reciprocating saw, and replaced with an equivalent part which is bonded in place."

The reduced repair time balances out the higher material cost, which means that, if the CFRP is damaged, the repair-cost is equivalent to that of a conventional car. With the cheaper plastic shell in the mix, the overall repair cost is lower; resulting in a 40% reduction in accident repair costs of an i3 compared to a 118d, which would reduce insurance premiums for business and private users alike.

According to Sattig, after discussions with NHTSA and the equivalent agency in Europe, and the insurance industries, a very low insurance loading has been agreed upon.

Conclusion

The evolution currently taking place in the use of composites is reminiscent of the early days of electronics in the automotive industry: Driven by a need for better performance, the industry had to find ways to meet the challenges.

Are the repair industry and relevant stake holders ready for composite structures? Right now, the answer would probably have to be, "No," but systems are in place to cope with the current requirements of a predominantly high value low volume market.
There’s also little doubt that in the very near future, as composite costs drop and volumes ramp-up, the techniques, equipment and above all skills will be available to comprehensively render effective field repairs of composite structures.

Already institutions such as Thatcham Automotive Academy, the UK-based training facility, offer composite training courses for the automotive industry. Course leader Mark Turner, a former McLaren employee who trained McLaren dealers worldwide, explains the motivation behind the course: "We expect to see an increasing use of these materials filtering down from the very high-end vehicles to the mainstream within a short space of time. Dealing with carbon fibre composites provides some unique challenges and technicians need to have the basic understanding that this course provides before they attempt to tackle a real world repair."

Sources:

• The Sun - Rowan Atkinson gets staggering £910,000 insurance payout after supercar crash (James Beale)
• Composites world – Automotive CFRP: Repair or replace? (Peggy Malnati)
• Business car manager - BMW’s electric revolution
• Autoblog green – BMW i3 EV will have lower insurance, repair costs thanks to carbon fibre (Sebastian Blanco)
• European Plastics News – Thatcham offers carbon fibre repair training

Peter Els is a technical writer for Automotive IQ