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HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

The time evolution of flow-induced structures in low-concentration worm-like micellar solutions is studied using direct visualization and rheological methods. The visualization measurements show growth of a new viscous shear-induced phase (SIP) starting on the inner wall of a Couette shear cell at a time t 1 after the commencement of shear flow. The SIP continues to grow across the shear cell until it fills the entire gap at a time t2. Rheological measurements show that the time t1 corresponds to the induction time for the increase in stress and that t2 corresponds to the plateau time for the saturation of stress. These measurements provide convincing evidence that the increase of stress with time results from the inhomogeneous growth of a new shear-induced phase in the flow cell. The growth of the new phase across the cell is approximately linear in time.

HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.