Abstract: A method for identifying stochastic information of a heterogeneous material utilizes physical loading measurements that are input into a global optimization process. The optimization process executes, in parallel, a force-driven non-linear finite element simulation and a displacement-driven finite element simulation of a constitutive model of the heterogeneous material. The constitutive models model the spatially varying random material properties (i.e. stochastic properties) using the Karhunen-Loeve expansion, thereby introducing the stochastic parameters, including spatial mean, spatial variance, and correlation length for example into the models. Stress and strain values for both the force-driven and displacement driven finite element analyzes are input into an objective function, whereupon the finite element simulations are updated after each iteration of the optimization process is performed until the objective function is minimized to a desired level.

Abstract: A method of using a paint sensor to observe stress distributions of a stressed substrate includes the steps of applying a composition including a paintable medium and a mechanoluminescence material to a substrate, allowing the composition to form a solid film on the substrate, allowing the substrate to be stressed following the formation of the solid film, and measuring the stress the substrate has undergone by determining the mechanoluminescence of the solid film. A composition for visualizing stress or crack distributions includes a paintable medium and a mechanoluminescence material dispersed therein.

Abstract: A method of using a paint sensor to observe stress distributions of a stressed substrate includes the steps of applying a composition including a paintable medium and a mechanoluminescence material to a substrate, allowing the composition to form a solid film on the substrate, allowing the substrate to be stressed following the formation of the solid film, and measuring the stress the substrate has undergone by determining the mechanoluminescence of the solid film. A composition for visualizing stress or crack distributions includes a paintable medium and a mechanoluminescence material dispersed therein.

Abstract: An apparatus for measuring mechanoluminescent light includes a chamber defining an enclosure for a portion of a structure to be monitored and providing an opening fitted onto the structure. The structure has a mechanoluminescent material thereon. The apparatus further includes an imaging sensor positioned and configured to take images of the mechanoluminescent material and an electronic controller in wired or wireless communication with the imaging sensor, the electronic controller being capable of controlling the properties of the imaging sensor and processing the images of the mechanoluminescent material.

Abstract: A sensor for visualizing stress includes a medium and a plurality of mechanoluminescence assemblies dispersed therein. A mechanoluminescence assembly can include a mechanoluminescence material and a coating material, where the mechanoluminescence material is at least partially coated with the coating material. A method of using the sensor can include applying the medium to a substrate and allowing the medium to form a solid film on the substrate. Methods of using the mechanoluminescence assemblies are also provided.

Abstract: An apparatus for measuring mechanoluminescent light includes a chamber defining an enclosure for a portion of a structure to be monitored and providing an opening fitted onto the structure. The structure has a mechanoluminescent material thereon. The apparatus further includes an imaging sensor positioned and configured to take images of the mechanoluminescent material and an electronic controller in wired or wireless communication with the imaging sensor, the electronic controller being capable of controlling the properties of the imaging sensor and processing the images of the mechanoluminescent material.

Abstract: A method for identifying stochastic information of a heterogeneous material utilizes physical loading measurements that are input into a global optimization process. The optimization process executes, in parallel, a force-driven non-linear finite element simulation and a displacement-driven finite element simulation of a constitutive model of the heterogeneous material. The constitutive models model the spatially varying random material properties (i.e. stochastic properties) using the Karhunen-Loeve expansion, thereby introducing the stochastic parameters, including spatial mean, spatial variance, and correlation length for example into the models. Stress and strain values for both the force-driven and displacement driven finite element analyses are input into an objective function, whereupon the finite element simulations are updated after each iteration of the optimization process is performed until the objective function is minimized to a desired level.