Luminescent photoelastic coating (LPC) methods are used to measure the full-field shear strain and its principal direction. These methods apply a liquid LPC onto the surfaces of the structures to be measured. To correct the effects of coating thickness non-uniformity on the quantitative shear strain measurements, a non-contact method is proposed for coating thickness measurements. The proposed method establishes a linear calibration curve between the thickness and the luminescent signal intensity of the test coating. The results show that the linear calibration curve of the intensity and the thickness of the LPC can be obtained by incorporating an appropriate concentration of the luminescent dye into the photoelastic coating. The correlation coefficient of this linear calibration curve is more than 0.999.
Advanced optical materials with rational designs and tunable light transmission have been drawing increasing interest due to their great potential in energy-efficient buildings and on-demand optical devices. Mechanoresponsive smart windows (SWs) can modulate light transmittance by mechanical actuation, showing high energy efficiency, low cost, and chemical stability. However, current research mainly focuses on tensile strain-responsive SWs that typically require a large strain to achieve optical transparency switching-which causes great inconvenience to practical application and fatigue damage to matrix materials. Herein, a novel shear-responsive SW with high strain sensitivity is fabricated by vertically fixing a Fe 3 O 4 @SiO 2 nanochains (NCs) array in an elastic polyacrylamide matrix. The flexible SW exhibits optically transparent with all NCs standing vertically to the SW surface at initial relaxation state, which enables a good shielding effect, with NCs tilting along the shearing direction as the strain applied. Critically, a rather small shear displacement (1.5 mm) applied on the surface of SW gives rise to tunable optical states varying from the transparency state of 65% transmittance to the opaque state of 10%. The as-prepared SW with novel tuning modulation, high shear strain sensitivity, and optical angle-dependence holds promising potential in smart windows, optical switches, anti-voyeurism, and etc.
Induced dipole dominant electrorheological fluid (ID-ERF) is a new type of ERF. After high energy ball milling (HEBM) process, dielectric particles produce a large number of oxygen vacancies, and the dipoles formed by the polarization of these oxygen vacancies provide excellent ER properties. ID-ERF has the advantages of high shear stress, low current density, long service life, anti-sedimentation, simple preparation method, etc. It should be a new generation of ERF material suitable for practical application. In this work, facing at the shortcomings of traditional particle MD simulation of ERF system, a coarse-grained molecular dynamics (CGMD) model is constructed. The evolution of ID-ERF is simulated under the conditions of no electric field and 5 kV/mm electric field. Proves that there is an adsorption layer of carrier liquid on the surface of ER particles, and shows BCT lattice arrangement under electric field. The sinusoidal shear strain is applied to the model, and calculate the variation of strain amplitude, loss factor, storage modulus and loss modulus. In addition, we prepared ID-ERF and tested its performance to compare with the simulation results.
危险品化学品经营许可证（带存储）