为了从微观层面揭示锚杆在复杂环境中的腐蚀破坏机理,将分子动力学方法引入到锚杆的腐蚀研究中,借助Materials studio软件建立分子动力学模型,引入到Lammps软件中进行分子动力学模拟,模拟研究了预应力锚杆在氯离子环境中的腐蚀特性,探究了氯离子溶液与锚杆表面间的微观作用规律。结果表明：在预应力和氯离子的耦合作用下,铁基体将吸收更多氧原子,促进氧原子与铁之间的结合,加速锚杆的氧化腐蚀钝化；预应力的施加削弱了锚杆内部原子的束缚,使得铁原子的运动趋势增大,更容易与其它原子相结合；氯离子会增大铁原子与氧原子的作用强度,促进铁与氧的结合,且氯离子会随着预应力的增大逐渐活跃；随着预应力增大,溶液中的氧原子由于更容易与铁发生反应形成稳定化学键,其运动特性逐渐减弱。氧化反应结束后铁基体表面会形成一层氧化膜,在氯化物溶液环境中,氧化层厚度明显增加,且预应力越大,氧化层越厚。

In order to reveal the corrosion and failure mechanism of bolts in the complex environments at a micro level, molecular dynamics methods were introduced into the corrosion research of bolts. A molecular dynamics model was established using Materials Studio, and the molecular dynamics simulations were conducted using Lammps. The corrosion characteristics of pre-stressed bolts in chloride ion environments were simulated and studied, and the micro interaction law between chloride ion solution and the surface of bolts was explored. The results show that under the coupling effect of pre-stress and chloride ions, the iron matrix will absorb more oxygen atoms, promote the binding between oxygen atoms and iron, and accelerate the oxidation corrosion passivation of the bolts; The application of pre-stress weakens the binding of atoms inside the bolts, increasing the movement trend of iron atoms and making it easier to combine with other atoms; Chloride ions will increase the strength of the interaction between iron and oxygen atoms, promoting the binding of iron and oxygen, and chloride ions will gradually become active with the increase of prestress; With the increase of pre-stress, the movement characteristics of oxygen atoms in the solution gradually weaken because they are more likely to react with iron to form stable chemical bond. After the oxidation reaction is completed, a layer of oxide film will form on the surface of the iron substrate. In the chloride solution environment, the thickness of the oxide layer significantly increases, and the greater the pre-stress, the thicker the oxide layer.

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国家自然科学基金项目（面上项目，重点项目，重大项目）