Search

The past 10–15 years have seen important extensions of the mortar method, a technique for joining dissimilar grids popularized by the domain decomposition community, to the more general problem of contact and impact interactions in finite element analysis. This development has taken place largely in response to several long-standing problems in computational contact mechanics: lack of robustness in solution of the nonlinear and nonsmooth equations of evolution; degradation of spatial convergence rates in problems involving nonconforming meshes on interfaces; lack of a variationally consistent technique for stress recovery on interfaces; and so on. This survey paper summarizes some of the major steps in development of mortar contact formulations. It begins with a basic summary of the mortaring idea in the context of tied contact, it discusses key concepts required for the extension of these methods to large deformation, large sliding formulations of contact-impact, and it previews new results where lessons learned from mortar contact formulations can be extended to a much broader class of interface mechanics applications, considering in particular enriched interface formulations and embedded interface approaches to fluid–structure interaction.

Students training to be educators frequently exhibit voice disorders prior to employment. To date, there exist no similar studies of future speech-language pathologists (SLPs). The study is designed as a prospective, nonrandomized survey. The objective of this study is to determine the voice problems of first year graduate students training to be SLPs. Participants were 104 first year graduate students majoring in speech-language pathology at two universities. The Quick Screen for Voice was administered. Participants who failed completed a questionnaire regarding voice problems, medical history, daily habits, and voice use. When responses further indicated voice-related problems, endoscopic examination was completed. Fourteen percent (N=15) of the participants failed the screening by demonstrating two or more abnormal voice characteristics. These included persistent glottal fry (present in all who failed), low habitual pitch, juvenile resonance, hoarse, breathy, or strained phonation, abnormally low pitch on sustained vowels, and voice breaks during the frequency range. Twelve percent (N=12) failed both the screening and follow-up questionnaire. Responses included self-reported dysphonia, medical history with voice-related side effects, difficulty with excessive voice use, and voice problems occurring daily or weekly. Endoscopic evaluation showed one participant with bilateral vocal nodules. The results suggest that voice problems among future SLPs (12%) are more common than the 3-9% reported in the general population and similar to the 11% previously reported for teachers. However, future SLP voice problems are less frequent than those reported among education majors (21%) and all college students (17%). Faculty should identify students with voice problems and emphasize optimal voice use in classroom and clinical settings.