凝固相变晶粒形核长大的数值模拟.doc

摘要 本文主要是把遗传算法（简称GA方法）的基本原理和基本思想用于到材料科学中模拟液态金属凝固结晶过程中的晶粒形核并长大，并且模拟了晶粒形核过程中的无规则运动模型。在此基础上，通过使用VB编程语言编程实现了用GA方法进行组织结构模拟。 文中详细地介绍了凝固相变原理，揭示了晶粒形核和长大的热力学和动力学。在具体模拟过程中，本算法基于最小能量原理和晶粒形核长大的动力学这两个基本原则进行模拟的，简单介绍了GA方法及其发展历程以及vb编程模拟系统，详细叙述了GA模拟方法，以及在二维坐标中用200x200个方形晶格点元素模拟晶粒形核并长大的过程和晶粒无规则运动的模型。模拟结果揭示了GA方法在模拟微观组织过程中的重要作用，该算例也说明了GA方法在模拟晶粒长大过程方面的直观性和有效性，并且简介GA方法在材料加工中其他应用。 最后，对晶粒长大的GA模拟进行总结。并归纳总结所用模拟算法的优缺点。在此基础上对所作课题做出展望。 关键词：遗传算法;凝固;晶粒形核；晶粒长大;模拟ABSTRACT This article mainly is the genetic algorithm (the i.e. GA method) of the basic principle and the basic thought use in the materials science in the simulation liquid metal coagulation crystallization process crystal grain shape nucleus and grow up, and has simulated in the crystal grain shape nuclear process non-regular movement model . In this foundation, through used the VB programming language programming to realize has carried on the organizational structure simulation with the GA method. In the article introduced in detail the principle of the coagulation changes, has promulgated the crystal grain shape nucleus and coarsening thermodynamics and dynamics. In the concrete simulation process, this algorithm carries on the simulation based on the smallest energy principle and crystal grain shape nucleus coarsening dynamics these two basic principles, introduced simply the GA method and the development course as well as the vb programming analogous system, narrated the GA simulation method in detail, as well as in the two-dimensional coordinates the process and the crystal grain non-regular movement model which and grows up with the 200x200 square shape lattice point element simulation crystal grain shape nucleus. The analogue result has promulgated the GA method in the simulation microscopic organization process vital role, this example also showed the GA method in the simulation microscopic organization process vital role, this example also showed the GA method in simulation crystal growth process aspect intuitive and the val