Non-destructive test methods are often used in tunnel construction to check the required lining thicknesses. Hereby, mostly ground penetrating radar, impact-echo and ultrasonic echo are applied. However, the current knowledge and experience is largely limited to testing the concrete thickness of double-shell tunnels. Problems with the application of non-destructive test methods can arise, when ...

the non-destructive meyer method was evaluated to determine the bark volume of beech (fagus orientalis lipsky) stands in north of iran. the sample size was 185 standing trees collected from 4 geographical aspects (north, south, west and east) aspects. the constant k values and bark thickness (2e mm) of 185 standing trees were used to calculate the bark volume by the meyer method. in this study,...

This chapter discusses the principle and application of two model‐based algorithms for processing non‐dispersive and dispersive ground penetrating radar (GPR) data over layered medium under monostatic antenna configuration. Both algorithms have been selected for their super‐time resolution capability and reduced computational burden; they allow GPR to measure a layer thickness smaller than the ...

in this paper a new method for nondestructive testing or nondestructive evaluation is proposed for glass-epoxy composite. for this purpose, impact-echo is used to evaluate the properties of composite materials, detecting internal defects and thickness measurement. in the impact-echo method a steel ball impacts on a composite plate and generates stress waves or p-waves which will be transferred ...