Objective To determine the relative incidence, prevalence, costs and impact on disability of 8 common conditions treated by rehabilitation professionals. Design Structured review of the literature Setting United States Participants N/A Interventions N/A Main Outcome Measures disease associated incidence, prevalence, direct and indirect costs and impact on activity and work limitations. Results Back pain and arthritis (osteoarthritis and rheumatoid arthritis) are the most common and costly conditions that we examined, affecting over 100 million individuals and costing over $200 billion per year. Traumatic brain injury, while less common than arthritis and back pain, carries enormous per capita direct and indirect costs, mostly due to the young age of those involved and the severe disability that it may cause. Finally, stroke, which is often listed as the most common cause of disability, is likely second to both arthritis and back pain in its impact on functional limitations. Conclusions Of the common rehabilitation diagnoses we studied, musculoskeletal conditions such and back pain and arthritis likely have the most impact on the health care system due to their high prevalence and impact on disability.

That contribution to transformation plasticity of steels arising from the so-called Greenwood-Johnson mechanism is often described using the model developed by Leblond and coworkers. This model made the assumption of purely plastic behaviour. It is extended here to incorporate viscous effects, which are present during some transformations, especially at high temperatures. The predictions of the original and extended models are compared to experimental results for a material for which the second contribution to transformation plasticity, due to the so-called Magee mechanism, is known to be negligible, and it is shown that the incorporation of viscous effects into the model significantly improves its predictions.

Prediction of welding residual distortions is more difficult than that of the microstructure and residual stresses. On the one hand, a fine mesh (often 3D) has to be used in the heat affected zone for the sake of the sharp variations of thermal, metallurgical and mechanical fields in this region. On the other hand, the whole structure is required to be meshed for the calculation of residual distortions. But for large structures, a 3D mesh is inconceivable caused by the costs of the calculation. Numerous methods have been developed to reduce the size of models. A local/global approach has been proposed to determine the welding residual distortions of large structures. The plastic strains and the microstructure due to welding are supposed can be determined from a local 3D model which concerns only the weld and its vicinity. They are projected as initial strains into a global 3D model which consists of the whole structure and obviously much less fine in the welded zone than the local model. The residual distortions are then calculated using a simple elastic analysis, which makes this method particularly effective in an industrial context. The aim of this article is to present the principle of the local/global approach then show the capacity of this method in an industrial context and finally study the definition ofthe local model.

In most numerical simulations of welding, viscoplastic phenomena are neglected, because of shortness of the process. The aim of this paper is to accurately assess the effect of such phenomena upon predicted residual stresses and distortions, through comparison of simulations using both elastic-plastic and elastic-viscoplastic constitutive laws, and experiments. These experiments are performed on a mock-up developed at INSA Lyon and especially designed for the study of the material behaviour in the heat affected zone of a welded component; this mock-up is sufficiently simple to allow for cheap 2D axisymmetric simulations, but nevertheless complex enough to represent a real welded structure, albeit in a schematic way. It is found that incorporation of viscous effects into the description of the material behaviour has a marginal influence upon predicted residual stresses but a significant one upon predicted residual distortions, which agree much better with measured ones when viscous effects are accounted for.STWJ/431