An Efficient Visual Inspection Method Applicable to Low Energy Impact Damage of Composite Materials

Abstract

An efficient visual detection method for low-energy impact damage in composite materials. This method uses a series of impact tests to obtain the absorbed impact energy E of the brittle-tough double-layer paint film. 吸收 , and then determine the impact energy threshold E of the composite material BVID , carry out the impact test on the prepared brittle-tough double-layer paint film / composite material, and determine the E 吸收 , combined with the loaded impact energy to calculate the remaining impact energy E directly acting on the composite material 剩余 ; To detect impact damage, when E 剩余 ≥E BVID , the visual impact damage is almost invisible. This method establishes E 吸收 ‑Paint film crack growth pattern‑E 剩余 -E BVID The corresponding relationship between the impact damage can be effectively amplified, and the internal damage degree of the composite material part can be evaluated through the equivalent evaluation of the crack propagation form of the paint film after impact, which reduces the damage caused by the damage to the subsequent service process and avoids non-destructive testing.

Description

technical field [0001] The invention belongs to the technical field of non-destructive testing of composite materials, and relates to a high-efficiency visual detection method suitable for low-energy impact damage of composite materials, and is suitable for the judgment process of the internal quality of composite material parts after impact damage. Background technique [0002] Composite parts are extremely sensitive to external impacts. During their service, impact damage is the main damage mode of composite structures. For high-energy impacts, most of the damage caused is penetrating damage, and the surface will show For relatively obvious damage features, inspectors can easily determine the repair or replacement process to maintain the damaged area through the surface damage features supplemented by non-destructive testing conclusions, so as to avoid the impact of internal damage on the service process of composite materials. However, compared with high-energy impacts, l...

AI Technical Summary

Problems solved by technology

However, compared with high-energy impacts, low-energy impacts have a higher probability of occurring during the service of composite parts, and generally do not cause visually detectable damage to the impacted surface, and it is difficult for inspectors to pass through the surface of the part. Directly observe and describe the structural damage status. If the internal damage detection process is not carried out, the workpiece may experience large internal damage without any signs on the surface, which will seriously affect the safety and reliability of the structure.

Therefore, it is necessary to use a large number of non-destructive testing methods such as ultrasonic C-scan and X-ray to evaluate the damage form and damage degree. Not only there are problems such as large investment in testing equipment and complicated operation process, but also relatively high requirements for the technical level of testing personnel and testing environment. High, for the internal damage judgment process of large-scale composite parts in service, it cannot meet its fast and efficient detection requirements