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A technique has been developed for producing Light Fibers with Precision Lighting Elements, which emit side light in carefully controlled patterns for exterior lighting applications. Target specifications can now be satisfied with light delivered from a very small, robust package. Conventional lenses and reflectors are not required. Three exterior applications have been targeted: the Center High Mounted Stop Lamp (CHMSL), a Side Marker, and an Emergency Flasher. An optical model of each application has been built, for which basic input parameters are target distribution, fiber diameter, and fiber length. Fiber cores are manufactured with the desired optical elements; cladding and a reflective coating over the notches complete the Precision Lighting Element. Measured intensity distributions from prototypes meet the modeled performance expectations.

This paper will discuss factors which influence attenuation in light fiber systems. These factors include bulk properties of the core material and the cladding material, as well as the characteristics of the core-cladding interface.

Because of the increasing concern with vehicle weight, there is an interest in lightweight materials that can serve several functions at once. Here we consider the vibration damping performance provided by an “acoustical” material (i.e., a fibrous layer that would normally be used for airborne noise control). It has been previously established that the vibration of panel structures creates a non-propagating nearfield in the region close to the panel. In that region, there is an oscillatory, incompressible fluid flow parallel to the panel whose strength decays exponentially with distance from the panel. When a fibrous medium is placed close to the panel in the region where the oscillatory nearfield is significant, energy is dissipated by the viscous interaction of the flow and the fibers, and hence the panel vibration is damped. The degree of panel damping is then proportional to the energy removed from the nearfield by the viscous interaction with the fibrous medium.

A multilayer acoustic treatment constructed of fibrous acoustic absorption material combined with dissipative acoustic material achieves a low profile and is lightweight and multi-functional, with properties that are desirable for NVH (noise, vibration, and harshness) treatments. The dissipative material consists of microfibers and acoustically active particles; this material was introduced in the last SAE NVH conference: A Novel Dissipative Acoustic Material [1]. In this paper, the acoustic performance of the multilayer treatment was evaluated by using random incidence absorption and transmission loss measurements, as well as in-vehicle experiments. Absorption and transmission loss were additionally modeled using the transmission matrix method (TMM). In the in-vehicle test, an OEM wheelhouse liner with Trim, for an SUV, was evaluated utilizing this new multilayer 3M treatment.