Basalt-fiber-reinforced polymer (BFRP) composites, utilizing a natural high-performance inorganic fiber, exhibit excellent weathering resistance, including tolerance to high and low temperatures, salt fog, and acid/alkali corrosion. They also possess superior mechanical properties such as high strength and modulus, making them widely applicable in aerospace and shipbuilding. This study experimentally investigated the mechanical properties of BFRP plates under various strain rates (10⁻⁴ s⁻¹ to 10³ s⁻¹) and directions using an electronic universal testing machine and a split Hopkinson pressure bar (SHPB).The results demonstrate significant strain rate dependency and pronounced anisotropy. Based on experimental data, relationships linking the strength of BFRP composites in different directions to strain rate were established. These relationships effectively predict mechanical properties within the tested strain rate range, providing reliable data for numerical simulations and valuable support for structural design and engineering applications. The developed strain rate relationships were successfully validated through finite element simulations of low-velocity impact.

As a natural high-performance inorganic fiber, basalt fiber material possesses excellent weathering properties, such as resistance to high and low temperatures, salt fog corrosion, and acid and alkali corrosion. It also exhibits superior mechanical properties, including high strength and high modulus, making it widely used in military fields such as aerospace and shipbuilding. In this study, the mechanical properties of basalt fiber plates in different directions under various strain rates were experimentally investigated using an electronic universal testing machine and a split Hopkinson pressure bar (SHPB) setup. The results indicate that the basalt fiber plates exhibit a significant rate-dependent behavior and pronounced anisotropy. Based on the experimental results, the relationship between the strength values of basalt fiber materials in different directions and strain rates was established. This formula can effectively predict the mechanical properties of basalt fiber under different strain rates, providing reliable data for numerical simulations and valuable support for structural design and engineering applications under various strain rate conditions. The strain rate relationship developed in this study has been effectively validated in finite element simulations of low-velocity impact.

The number of hologram points in near-field acoustical holography (NAH) for a vibro-acoustic system plays a vital role in conditioning the transfer function between the source and measuring points. The requirement for many overdetermined hologram points for extended sources to obtain high accuracy poses a problem for the practical applications of NAH. Furthermore, overdetermination does not generally ensure enhanced accuracy, stability, and convergence, owing to the problem of rank deficiency. To achieve satisfactory reconstruction accuracy with underdetermined hologram data, the best practice for choosing hologram points and regularization methods is determined by comparing cross-linked sets of data-sorting and regularization methods. Three typical data selection and treatment methods are compared: iterative discarding of the most dependent data, monitoring singular value changes during the data reduction process, and zero padding in the patch holography technique. To test the regularization method for inverse conditioning, which is used together with the data selection method, the Tikhonov method, Bayesian regularization, and the data compression method are compared. The inverse equivalent source method is chosen as the holography method, and a numerical test is conducted with a point-excited thin plate. The simulation results show that selecting hologram points using the effective independence method, combined with regularization via compressed sensing, significantly reduces the reconstruction error and enhances the modal assurance criterion value. The experimental results also support the proposed best practice for inverting underdetermined hologram data by integrating the NAH data selection and regularization techniques.