A method for calculating the axisymmetric response of a two-layered half-space under dynamic concentrated loading

✍ Scribed by Q. Grimal; S. Naı̈li; A. Watzky

• Publisher: Elsevier Science
• Year: 2004
• Tongue: English
• Weight: 396 KB
• Volume: 276
• Category: Article
• ISSN: 0022-460X
• DOI: 10.1016/j.jsv.2003.08.037

✦ Synopsis

The transient response of a linearly elastic structure made of a layer overlaying a half-space, subjected to a normal point force on its free surface, is investigated. Both welded contact and frictionless sliding are considered at the interface. This paper presents a method to calculate the response, for a wide range of loading durations ðTÞ; on the axis of symmetry of the configuration (in the layer and the half-space). Equations of the boundary-value problem are manipulated in an integral transform domain and the Cagniard-de Hoop method is used. The final form of the exact analytical solution is a sum of contributions corresponding to the rays of the generalized ray theory; little computational effort need be developed for evaluating each contribution. While this theory has only been used to obtain early-time responses, longtime responses-up to 30 times the transit time of P-waves in the layer-have been calculated for this study. This work was conducted to help characterize the stress transmitted in the human lung (half-space) when the thoracic wall (layer) is subjected to a non-penetrating impact. Depending on T; multiple reflections of waves in the layer or typical low-frequency response are observed. The influence of the contact condition with respect to T is elucidated.