| The industrial pipelines are used in all aspects of national product, so study on rupture failure of impacted pipe is of great significance for the design and protection of pressure pipeline. Applied the impact dynamics principle, research on the dynamic reponse and rupture failure of pipelines under the impact of different missiles was investigated by using ANSYS/DYNA finite element software combined with the self-developed APDL language.Major work and conclusions are following:(1) The large deformation and damage of impacted pipelines were reviewed. The previous research results and existing shortages were introduced following aspects:tube's impact damage, forward penetration failure, oblique impact failure, penetration failure mode and damage on the tube of internal filling medium and pressure. Based on these analysis, established beginning point, research content and technical course of this paper.(2) By using ANSYS/DYNA finite element software, established the FE model of pipelines impacted by missiles and verified the model's correctness. It is found that there is a great effect of impact region and grid density on the simulation accuracy.(3) Taking the example of outer diameter Do=114mm straight pipe and Do=45mm elbow bend which were subjected to different missiles, analyzed the penetration failure mode and damage process of pipelines. It is found that the penetration failure mode is petalling after the nose diameter Dm=9mm hemispherical-nosed and 90°conical-nosed missiles penetrated t=1.5mm straight pipe; the penetration failure mode are dishing, plugging and tearing respectively after Dm≥27mm hemispherical-nosed,90°conical-nosed and Dm≥9mm flat-nosed missiles penetrated t≥1.5mm straight pipe. The curvature-diameter ratio R/Do=2 elbow bend which is penetrated by Dm=5mm hemispherical-nosed missile belongs to petalling failure mode; the failure mode are dishing, plugging and laceration tearing respectively after Dm≥15mm hemispherical-nosed, Dm≥5mm flat-nosed and 90°conical-nosed missiles penetrate elbow bend.(4) Studied the defromation of thin and thick straight pipes under external lateral impact by hemispherical-nosed, flat-nosed and conical-nosed missiles; rupture failure characteristic; Relationship of critical rupture kinetic energy Er with Do, Dm, ratio between missile length and diameter lm/Dm (missile mass) and semi-cone angleΨ. It is found that the thin tube deformation is larger than thick tube's under Er. Rupture time of thick tube is less than thin tube's clearly; Er decreases with the increase of Do and increases as the lm/Dm increases. Under the impact of hemispherical-nosed and flat-nosed missiles, Er increases with the increase of Dm, for 90°conical-nosed missile, Er first increases and then decreases as the Dm andΨincrease.(5) Studied the defromation of thin and thick elbow bend under inner impact by flat-nosed hemispherical-nosed and conical-nosed missiles; rupture failure characteristic; Effects of Er on Do, t/Do, Dm/t, lm/Dm (missile mass)Ψand R/Do. It is found that under Er, deformation of thick tube is more or less the same as thin tube's and thin tube's deformation increases with the increase of R/Do. Rupture time of thick tube is less than thin tube's. Er is nothing to do with Do and increases with the increase of t/Do and R/Do. With the hemispherical-nosed missile impacted, Er increases with the increase of Dm/t and lm/Dm; with the flat-nosed missile missile impacted, Er increases with the increase of Dm/t and shows stability change as lm/Dm increases; with the 90°conical-nosed missile impacted, Er increases as the lm/Dm increases and first increases and then decreases with the increase of Dm/t andΨ, proposed the fitting formula of Er andΨ. When both Dm/t and lm/Dm changing, the missile mass plays a leading role. And proposed the fitting formula of Er with Dm/t and lm/Dm of hemispherical-nosed, flat-nosed and conical-nosed missiles.
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