CW Blog

An ambitious multi-year program by Germany’s System integrated Multi-Material Lightweight Design for E-mobility (SMiLE) consortium has developed a demonstrator automotive load floor module that is part of a larger hybrid body-in-white (BIW) structure and that shows great promise for use of composites and non-ferrous metals in a medium-volume production environment. This battery-electric vehicle’s (BEV’s) rear load floor is comprised of two types of thermoplastic composite, plus metallic profiles and inserts. It functions as the floor of the trunk and rear passenger compartment. In turn, it’s adhesively and mechanically joined to a second, hybrid/thermoset composite load floor, which is resin transfer molded (RTM’d) from carbon fiber-reinforced epoxy with metallic inserts and local sandwich structures containing polyurethane-foam cores. This structure is the floor for the front half of the vehicle and holds its batteries. The complete load floor module is bonded and screwed to aluminum rockers/side rails, which are themselves bolted to crossbeams on the vehicle’s aluminum monocoque. The entire load floor module demonstrator was designed to reduce mass and provide significant crash energy absorption for a series-production vehicle with build volumes of 300 cars/day.

Consortium members who worked on the rear load floor included automakers Audi AG (Ingolstadt, Germany—also leader of the entire SMiLE program) and Audi owner Volkswagen AG (Wolfsburg, Germany); Karlsruhe Institute of Technology’s Institute of Vehicle System Technology (KIT-FAST, Karlsruhe, Germany); Fraunhofer Institute for Chemical Technology (F-ICT, Pfitztal, Germany, leader for both front and rear load floor projects), and Fraunhofer Institute for Mechanics of Materials (F-IWM, Freiburg, Germany); thermoplastic composites supplier BASF SE (Ludwigshafen, Germany); machinery OEM Dieffenbacher GmbH Maschinen- und Anlagenbau (Eppingen, Germany), and toolmaker/molder Frimo Group GmbH (Lotte, Germany).

Read More

It all started with the Ansari XPrize. Wealthy space enthusiasts Anousheh and Amir Ansari offered $10 million to the first private enterprise, worldwide, “to build a reliable, reusable, privately financed, manned spaceship capable of carrying three people to 100 km [62 miles] above the Earth’s surface twice within two weeks,” says the Ansari XPrize website.  

The award, given in 2004, went to Mojave Aerospace Ventures (MAV, Mojave, CA, US), owned and funded by Microsoft co-founder Paul Allen for spaceship technology engineered by Burt Rutan and his Scaled Composites team at the Mojave Spaceport. The spaceship that reached the goal was an all-carbon fiber composite structure named SpaceShipOne. In one of the many departures from the ordinary in this venture, the spaceship did not launch from Earth’s surface, but was delivered part of the way to its destination by the (also) carbon fiber composite WhiteKnight. Dubbed the mothership, WhiteKnight was designed to replace the first stage of a traditional rocket used to launch a craft from Earth’s surface. When WhiteKnight reached its target altitude, SpaceShipOne was released from its mothership and a dedicated rocket on SpaceShipOne provided the second-stage boost, driving the spaceship up to its suborbital goal.

Read More

The Institute for Advanced Composites Manufacturing Innovation’s (IACMI, Knoxville, TN, US) and CompositesWorld will host a Compression Molding Workshop on January 17, 2019. The limited seating workshop will take place at IACMI’s Scale-Up Research Facility (SURF, Detroit, MI, US) and offers OEMs and composites fabricators an opportunity to learn about two existing technologies:

The workshop aims to enable OEMs and fabricators seeking to expand composites penetration in automotive and other end markets.

Read More

Having full visibility into a composite and/or adhesive bondline during cure has been an issue for decades. Current temperature sensors — thermocouples — are too large to be embedded without causing a defect in the part. Thus, it is now only possible to read temperature at the surface and perimeter of parts and bonded repairs. It is difficult to know the temperature of an adhesive at the bottom of a repair patch, inside a thick fuselage or wing skin laminate or between those skins and thick stringers. Yet, that temperature is crucial for proper resin flow, wetting and cure.

Currently, the composites industry  compensates for this shortcoming by spending months and millions of dollars testing to ensure that estimated time and temperature recipes do indeed complete cure and produce the necessary properties. Despite this, suppliers still spend many man-hours and dollars each year reviewing and certifying parts where thermocouples fail or where leading/lagging thermocouples are sufficiently outside of prescribed boundaries to cast doubt on properties and in-flight performance.

Read More

Prosthetics and orthotics often take advantage of composite materials’ strength and durability. One application in particular that benefits from composites are sockets, custom-shaped, hollow forms into which an amputee’s stump fits; sockets also include hardware that accepts limb or hand/foot attachments. Manufacturer Coyote Design (Boise, ID, US) is well known for its composite “definitive sockets” (as distinguished from temporary, typically plastic, test sockets, for fit testing). To produce a socket, a hollow cast is made of the patient’s stump and is then filled with plaster to create a positive shape. That plaster shape, fitted with a hollow pipe for handling inserted in the center, becomes the mold for the composite socket layup. The layup is wet-out with resin with the help of a vacuum (via the hollow pipe) and cured at room temperature, often with the help of a heat blanket, says Coyote Design’s Rod Smith, director of marketing. 

Dale Perkins, Coyote Design’s cofounder, was an early adopter of composites and was not afraid to try new or exotic composite reinforcements. For example, one amputee patient and avid outdoor enthusiast (and who later summitted Mt. Everest) suggested using aramid for a tough prosthetic. However, several sockets made with that fiber failed, due to a lack of adhesion to the polyester resin Perkins was using at the time. Materials improved with the advent of carbon fiber braided tubes, or “socks,” wet out with epoxy resin or acrylic-modified epoxy. Carbon fiber prosthetic sockets exhibited good mechanical performance, but the material’s brittleness caused a high rate of cracking failure, and patients often reported uncomfortable stiffness. In addition, manufacturing with carbon fiber required masks, protective gear and dust collection systems for health and safety.

Read More