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Long fiber thermoplastics (LFTs) are increasingly being used in automotive applications for front-ends, bumper beams, dashboards, and under body shields. They have a significant potential for mass-transit applications in buses, trucks, and railroad vehicles. The LFTs are processed with a thermoplastic matrix such as polypropylene (PP) or polyamide (PAI) reinforced with long glass (or carbon, aramid, etc.) fibers, with starting fiber lengths >12 mm, through a pultrusion processing method. The LFT components are typically produced using extrusion-compression molding. In the present work, a bus seat was chosen as a candidate component to assess the viability of LFT technology to reduce weight and cost, without compromising performance over presently used designs. A conservative estimate of 43% weight reduction and 18% cost reduction per seat was predicted over presently implemented seat designs that contain a circumferential steel frame. Cadpress-Thermoplastic (EXPRESS) compression molding software for LFTs was utilized for the process modeling. Flow simulation during the compression molding of E-glass/PP LFT was conducted. Finite element stress analysis was conducted to verify mechanical properties developed as a result of fiber orientation and distribution after flow simulation. This article covers the design, process modeling, component verification, and manufacturing studies conducted for the LFT bus seat.

Sandwich composites find increasing use as flexural load bearing lightweight sub-elements in air / space vehicles, rail / ground transportation, marine and sporting goods. The core materials in these applications is usually balsa, foam or honeycombs, while laminated carbon or glass are used as facesheets. A limitation of traditional sandwich configurations is that the space in the core becomes inaccessible once the facesheets are bonded in place. Significant multi-functional benefits can be obtained by making either the facesheets or the core, space accessible. Multi-functionality is generally referred to as value added to the structure that enhances functions beyond traditional load bearing. Such functions may include sound / vibration damping, ability to route wires or embed sensors. The present work considers traditional core materials of nomex and aluminum honeycombs that possess functional space accessible facesheets, and their low velocity impact (LVI) response.

Approved for public release; distribution is unlimited.ii REPORT DOCUMENTATION PAGE Form Approved OMB No. 0704-0188Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing the burden, to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. REPORT DATE (DD-MM-YYYY)September 2009 ARL-TR-4996 SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR/MONITOR'S ACRONYM(S) SPONSOR/MONITOR'S REPORT NUMBER(S) DISTRIBUTION/AVAILABILITY STATEMENTApproved for public release; distribution is unlimited. SUPPLEMENTARY NOTES ABSTRACTBallistic tests were carried out on the relatively new titanium alloy Ti-5Al-5V-5Mo-3Cr (Ti-5553), which was subjected to two heat treatment conditions. The two heat treatments provided high-strength plates which were solution treated and aged (STA) and high toughness plates that were beta-annealed, slow cooled and aged (BASCA). The ~13.9-mm-thick plates were evaluated for V 50 using 0.