Synopsis A method of manufacturing a bobbin-shaped specimen for testing concrete in direct tension is described. Direct tensile strength is related to tensile and compressive strengths as determined by standard tests and their changes with age are described. Data on the modulus of elasticity in compression and in tension at two exposure conditions are given, and the influence of age upon creep and creep recovery is established. The differences in behaviour of strength, modulus of elasticity, creep and creep recovery are discussed by considering the effects of load and storage environment upon the adsorbed water of the cement paste, and the suggested creep mechanism is a combination of the seepage and viscous shear theories.

Oral friction on the tongue surface plays a pivotal role in mechanics of food transport, speech, sensing, and hedonic responses. The highly specialized biophysical features of the human tongue such as micropapillae-dense topology, optimum wettability, and deformability present architectural challenges in designing artificial tongue surfaces, and the absence of such a biomimetic surface impedes the fundamental understanding of tongue–food/fluid interaction. Herein, we fabricate for the first time, a 3D soft biomimetic surface that replicates the topography and wettability of a real human tongue. The 3D-printed fabrication contains a Poisson point process-based (random) papillae distribution and is employed to micromold soft silicone surfaces with wettability modifications. We demonstrate the unprecedented capability of these surfaces to replicate the theoretically defined and simulated collision probability of papillae and to closely resemble the tribological performances of human tongue masks. These de novo biomimetic surfaces pave the way for accurate quantification of mechanical interactions in the soft oral mucosa.

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SYNOPSISIt is shown that, in comparison with a static stress, cyclic loading accelerates the non-elastic deformation of concrete. The resulting creep can be expressed as the sum of a mean-stress component and of a component which is dependent both upon the range of stress and upon the value of the mean stress.

The ability to simulate mixed lubrication problems has greatly improved, especially in concentrated lubricated contacts. A mixed lubrication simulation method was developed by utilizing the semi-system approach which has been proven to be highly useful for improving stability and robustness of mixed lubrication simulations. Then different variants of the model were developed by varying the discretization schemes used to treat the Couette flow terms in the Reynolds equation, varying the evaluation of density derivatives and varying the contribution of terms in the coefficient matrix. The resulting pressure distribution, film thickness distribution, lambda ratio, contact ratio, and the computation time were compared and found to be strongly influenced by the choice of solution scheme. This indicates that the output from mixed lubrication solvers can be readily used for qualitative and parametric studies, but care should be taken when making quantitative predictions.