3results about How to "Delayed expansion" patented technology

The invention discloses a preparation method for constructing a multistage micro-nano heterostructure based on combination of a laser melting deposition process and a laser shock peening means, which comprises the following steps of: printing by using dry TC4 alloy powder, accumulating a printed TC4 metal printing layer to form a TC4 metal micron layer, performing low-power laser shock peening on part of the TC4 metal micron layer to form a TC4 metal submicron layer, and forming the multistage micro-nano heterostructure. A TC4 metal printing layer is printed on the submicron layer and subjected to high-power laser shock peening to form a TC4 metal nano layer, a TC4 metal printing layer is printed on the nano layer and subjected to low-power laser shock peening to form a TC4 metal submicron layer, printing and cyclic operation are continued on the submicron layer to form a sample, and the sample is obtained through annealing treatment. According to the preparation method disclosed by the invention, a micron layer-nano sandwich composite layer-micron layer multi-stage micro-nano heterostructure is formed, crack propagation is effectively hindered, and the elongation of the material is improved, so that alloy strength and plasticity synergistic strengthening is realized.

This invention discloses a FRP-concrete composite beam with built-in damage self-monitoring and its construction method, belonging to the field of civil engineering structural technology. The composite beam includes a concrete slab, an FRP profile, a shear reinforcement layer, intelligent connectors, and a protective shell. The intelligent connectors penetrate the shear reinforcement layer and are anchored to the FRP profile. Strain sensing elements are embedded internally, and driving elements are externally located. When the preload of the connector decreases, the driving elements actively extend to restore the preload. The shear reinforcement layer is a perforated plate filled with a tough material to enhance the shear resistance of the interface. The protective shell is a U-shaped precast concrete shell that wraps around the FRP web, providing lateral restraint and protection. This invention achieves real-time monitoring of FRP-concrete interface damage and automatic preload compensation, significantly improving the shear performance, integrity, and durability of the structure. It has advantages such as self-sensing, self-repair, and easy construction, and is suitable for long-span bridges, marine engineering, and intelligent building structures.