Some observations from a parametric study of the behaviour of benders in a polyurethane rubber

• Type: Article in International Scientific Journal
• Date: 2007

Authors

Paul Greening (Author) Other; João Rio (Author) FEUP; Marcos Arroyo (Author) Other

Journal

Title: Rivista Italiana di Geotecnica

Vol. 41 No. 2

Pages: 48-55

ISSN: 0557-1405

Publisher: PATRON EDITORE S R L

Scientific classification

FOS: Engineering and technology > Civil engineering

CORDIS: Technological sciences > Engineering > Civil engineering > Geotechnics ; Technological sciences > Technology > Instrumentation technology > Sensors

Other information

Resumo (PT): This paper describes some observations taken from a series of tests in which a polyurethane rubber has been used as a soil substitute. The specification of the polyurethane is described as well as the techniques which were developed to mould it into a variety of shapes with consistent properties. The tip deflection of bender elements under excitation was characterized using a laser velocimeter both in air and also when protruding into a specimen. These results show that results taken from "self monitoring benders" are erroneous. Very thin synthetic samples allow us to establish the relationship between transmitter bender and receiver bender which are touching. Using the transfer function from this system it is possible to establish how to isolate the non-soil parts of subsequent transmissions. Significant crosstalk was experienced. This is characterized and the effect of artificially removing crosstalk on frequency domain measurements is discussed.

Abstract (EN): This paper describes some observations taken from a series of tests in which a polyurethane rubber has been used as a soil substitute. The specification of the polyurethane is described as well as the techniques which were developed to mould it into a variety of shapes with consistent properties. The tip deflection of bender elements under excitation was characterized using a laser velocimeter both in air and also when protruding into a specimen. These results show that results taken from "self monitoring benders" are erroneous. Very thin synthetic samples allow us to establish the relationship between transmitter bender and receiver bender which are touching. Using the transfer function from this system it is possible to establish how to isolate the non-soil parts of subsequent transmissions. Significant crosstalk was experienced. This is characterized and the effect of artificially removing crosstalk on frequency domain measurements is discussed.

Language: Portuguese

Type (Professor's evaluation): Scientific