The logical extension of discrete mass systems is one of an infinite number of masses. In the limit, this is a continuous system. Take the generalized beam-column as a generic representation:

Summarizing what we've looked at in elasticity, we have: 15 equations in 15 unknowns 3 equilibrium -6 strains -6 strain-displacement -3 displacements

As we've previously noted, we may often want to describe a structure in various axis systems. This involves... Transformations (Axis, Deflection, Stress, Strain, Elasticity Tensors) e.g., loading axes material principal axis Figure 7.1 Unidirectional Composite with Fibers at an Angle

Sources of Stresses and Strains Depends on type of structure Aircraft

Recall the definition of stress: o stress =\intensity of internal force at a point\ Figure 3.1 Representation of cross-section of a general body

Finite element wodel of a beam(Euler-Bernollia- governing eQuations

the finite derwent meThod Ir position of boundary conditions(olis plcewent) We had obtained the aesewbed finite element eeve Kik2∞ Kht K Ki

◼ 项目费用管理概述 ◼ 资源规划 ◼ 费用估算 ◼ 费用预算 ◼ 费用控制

论述了新型天线技术的发展现状。液体天线用离子液体或液态金属等构成天线,构造灵活,使用场合广泛;铁电材料通过可调的高介电常数特性获得辐射特性可变的天线;而薄膜天线依托柔性材料技术的进步,易于制作轻质复杂的天线,适用于航空航天领域;

The only practical way to accelerate something in free space is by reaction. The idea is the same as in air breathing propulsion (to push something backwards) but in rockets the “something” must be inside and is lost. Here is a revealing derivation of the thrust equation for vacuum: