Elastic Rod model of DNA演示动画。

南京大学金国均凝聚态物理学导论讲义英文版PartII，pdf格式，内容有： 5.1：Wave Propagation in Periodic and Quasiperiodic Structures 5.2：Electrons in Crystals 5.3：Lattice Waves and Elastic Waves 5.4：Electromagnetic Waves in PeriodicStructures 5.5：Quasiperiodic Structures 5.6：Waves in Quasiperiodic Structures

Concept Question Which of the following statements is correct? Uo=U for ALL elastic materials(1 Uo=OijEij-U0 ONLY for linear elastic materials Jo=-ijEii for a nonlinear elastic material Statements(1) and 3)

The change in volume or shape of an object that results from stress is called strain. The response of rocks to stress can be divided into - elastic response: rock returns to original shape - ductile or plastic response: permanent deformation without fracture; occurs above the so-called elastic limit

Which of the following statements is correct? 1. The PVD only applies to linear elastic materials 2. The PVD applies only to elastic materials, but they can be linear or non-linear 3. The PVD applies regardless of the constitutive behavior of the material

which generalizes to the statement. This reduces the number of material constants from 81 to 54. In a similar fashion we can make use of the symmetry of the strain tensor This further reduces the number of material constants to 36. To further reduce the number of material constants consider the conclusion from the first law for elastic materials, equation

3.064 Quiz 3- Sample Questions 1. Consider a unidirectionally reinforced fiber-matrix composite a)What elastic constants(relative to the fiber and transverse directions )are needed to describe this material?