In this paper, we describe an experimental study of concrete behavior under a uniaxial tensile load by use of the thermally-compensated Coda Wave Interferometry (CWI) analysis. Under laboratory conditions, uniaxial tensile load cycles are imposed on a cylindrical concrete specimen, with continuous ultrasonic measurements being recorded within the scope of bias control protocols. A thermally-com...

By using of combining theoretical model with empirical model, the nonlinear viscoelastic-plastic constitutive equations of soybean and cottonseed were developed on the basis of the creep test. The parameter inverse problem of constitutive model was proposed using improved particles swarm optimization. Numerical simulations of creep of soybean and cottonseed were carried out. The definition of c...

Introduction Inertial effects are ubiquitous and unavoidable in stress-controlled rheometry. Many readers of this Bulletin will have seen the kind of phenomena shown in the experimental data of Figure 1. If the fluid is sufficiently viscoelastic, inertio-elastic 'ringing' events (i.e. damped oscillations) are observed in the angular displacement measured at the start of a creep test, as a resul...

Theoretical analysis and finite element (FE) simulation have been carried out for a constant specific load rate (CSLR) indentation creep test. Analytical results indicate that both the representative stress and the indentation strain rate become constant after a transient period. Moreover, the FE simulation reveals that both the contours of equivalent stress and equivalent plastic strain rate u...

The creep and recovery of 5% carboxyl-terminated butadiene acrylonitrile (CTBN) modified epoxy shape memory polymers (SMP) was studied. The results were compared with those for the unmodified epoxy SMP. The glass transition temperatures (Tg) were determined using Advanced Rheometric Expansion System (ARES). The creep behavior of the unmodified epoxy and 5wt.% CTBN modified epoxy SMP were studie...

Creep compliance measurements were shown to be effective in characterizing the elastic, retarded elastic, and viscous properties of polysulphide, silicone, and polyether impression materials. The test is particularly valuable in that the creep compliance was independent of load, allowing the mechanical properties to be represented by a single total creep compliance curve which can be used to de...

A new experimental method which allows the direct separation of the components of drying creep due to micro cracking and stress-induced shrinkage is developed, demonstrated and validated. The hasic idea is to compare the curL'CIture creep of heams suhjected to the same hending moment hut rery different axial forces. The results confirm that drying creep has two different sources: microcracking ...