Failure Of Materials Or Structures Under Continuous Wave Laser And Mechanical Load

Laser is widely used in industry, medicine, commerce, communication, militaryfields as the development of laser technology. The action of laser to matter is a seriesof complex physical and chemical changes. When laser irradiate the materials orstructures’ surfaces as an efficient heat source, the materials or structures are heated,melted or ablated. Those can result in that materials strength reduces or structureshave defects and failure or damage finally. It is of great significance to research thefailure mechanism and the effect laws of correlatively parameters on the damagetime for materials or structures under force load and laser irradiation. It can providemany references for materials and the design structure of laser protection.This paper tested the failure time of aluminum alloy5A03specimen, compositeT700/603laminated specimen and aluminum alloy5052cylindrical shell specimenunder the pre-loaded and the continuous wave laser irradiation in experiment. Thefailure mechanisms were analyzed and the effects of correlatively parameters on thefailure time were studied by data fitting for different material or structure on thatcondition. The main contents are follows:(1)At room temperature, the mechanical properties about the elastic modulus,strength and yield limit were tested for aluminum alloy in tensile experiment. Thefailure experiments were designed for aluminum alloy specimens under pre-loadedand laser irradiation and the fracture times were tested. The failure modus andmechanism were analyzed after observing the processes. The aluminum alloyspecimens have fractured as material is softened under pre-tensile-load and laserirradiation. The relationships between the fracture times are exponentially and laserpower density, linear and the pre-load as well as quadratic function and the specimenthickness.(2)At room temperature, the elastic modulus, tensile strength and compressionstrength were tested for composite laminated by tensile and compressionexperiments. The experiments of failure were designed for composite laminatedspecimens under pre-loaded and laser irradiation and the failure times were tested.The composite laminates have failure as the layers from surface to inside are ablatedunder pre-tensile-load and laser irradiation. The composite laminates are snapped asmatrix resin is softened under pre-compression-load and laser irradiation. The relationships between the fracture times are exponentially and laser power density,linear with the pre-load as well as quadratic function and the specimen thickness.(3)The curve on axial compression force-displacement for cylindrical shellspecimen was obtained by axial buckling experiment. The failure experiments weredesigned for cylindrical shell specimens under pre-loaded and laser irradiation andthe failure times were tested. The cylindrical shell specimens have a destruction of“collapse” as structural strength was reduced under axial pre-compression-load andlaser irradiation. The laser emissive energy thresholds of specimen “collapse”destruction can increase with decreasing load and which is zonal distribution.