In the case of sandwich beams, if the material of the faces has much larger modulus of elasticity than the material of the core, then it is ok to disregard the normal stresses in the core and assume that the faces resist all longitudinal bending stresses.

Question

BlackTom AI · Accepted Answer

In evaluating a statement about sandwich beams, it helps to separate the roles of the faces and the core in bending.
Option 1: True. The classic sandwich-beam theory states that when the face sheets have a much higher modulus of elasticity than the core, the faces predominantly carry the longitudinal bending stresses while the soft core mainly provides shear transfer and keeps the faces at a fixed separation. In this common regime (large E_f/E_c ratio), neglecting normal stresses in the core is a simplifying assumption that often yields good first-order results, because the core undergoes small axial strains while the faces experience the majority of the bending stress.
Option 2: False. Although the high-contrast condition just described makes it reasonable to minimize core normal stresses, it is not universally valid to completely disregard them. The core can still experience nonzero axial/normal stresses due to Poisson effects, geometric nonlinearity, bending-shear coupling, and any deviations from the idealized thin-face/low-density-core model. In some designs, especially where thicknesses are not extreme or where load paths induce significant core stiffness, neglecting core normal stresses can lead to error.

Therefore, the statement is conditionally correct under the common assumption of a very stiff faces / soft core with large E_f/E_c, but it is not an unconditional truth applicable to all sandwich-beam configurations. The key caveat is the ratio of moduli and the level of modeling accuracy required for the problem at hand.

In the case of sandwich beams, if the material of the faces has much larger modulus of elasticity than the material of the core, then it is ok to disregard the normal stresses in the core and assume that the faces resist all longitudinal bending stresses.判断题

类似问题

Is the following statement true or false? In the products of methylation-hydrolysis, every -OH group corresponds to the position of a glycosidic bond in the starting polysaccharide.

Which of the follwoing structures represents amylopectin?

Which of the following is true about an aldopentose?I. It is a monosaccharide.II. It contains a CHO groupIII. It is a disaccharide.IV. It is an oligosaccharide.

For stock A, we have 𝛽 𝑖 = 0.70. Suppose the expected market risk premium next year is 9% and the risk-free rate is 3%. What is the expected return of this stock based on the CAPM? (Please answer in % and round to 2 decimal places. If the answer is 8.057%, then in the box, write 8.06)

The following graph shows the Security Market Line in the current economy. If a stock has a β of 1.2, what is the expected return of this stock based on the CAPM? (Please answer in % and round to 2 decimal places. If the answer is 8.057%, then in the box, write 8.06)

更多留学生实用工具

智能学习助手

风格化写作助手

论文查重助手

文献引用助手

课堂转译助手

课堂笔记助手

Quiz搜索助手

学校历年真题

智能刷题助手

智能匹配练习

希望你的学习变得更简单