【Daily Question】 【AC Version for Static Equipment...Question 65】 March 6, 2019 – Revised multiple-choice questions...Everything is going well

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This post was last edited by kareale88 on 2019-3-6 at 14:16: bg4.png【Daily Question】【Static Equipment Discussion Forum...Question 65】 March 6, 2019 – Revised multiple-choice questions...Everything is going well........................................................................... The final voting stage for the 2018 “Top 10 Outstanding Members of Haichuan” has ended – hope you’ll be nominated for this year’s list! Wishing all my friends by the seas and rivers: happiness every year, a harmonious family life, good fortune and success, smooth circumstances and good health, and prosperity throughout their lives! ........................................................................... Answers (multiple choice, multiple choice, multiple choice) please fill in in order. Reward rules: 1 wealth for participation, 3 wealth for each correct answer, up to a maximum of 10 wealth. ........................................................................... 1. For a device with a diameter of 2400 and a cylinder length of 3200 (including the straight edges), the length for external pressure calculation when the ends are hemispherical heads is ( ), and the length for external pressure calculation when the ends are elliptical heads is ( ). A、4000, 4200 ； B, 3800, 4000 ； C, 3600, 4200 ； D, 4000, 3600 ； --------------------- 2. When a load is applied, in certain small local areas near the section where there is a sudden change, the stress value increases sharply; whereas slightly away from this area, the stress decreases significantly and tends to become uniform. This phenomenon is known as stress concentration. （） A、Correct B、Incorrect --------------------- 3. Generally, the heat treatment of pressure vessels is classified into four types based on its purpose: post-welding heat treatment, heat treatment to restore mechanical properties, heat treatment to improve mechanical properties, and degassing treatment. ( ) A. Correct B. Incorrect --------------------- Correct answers: 1. D 2. A 3. A 1. Comment: This is a question prone to errors; many people do not understand thoroughly how to calculate lengths under external pressure. This question helps us grasp that concept more clearly. Derived from GB/T150.3-2011 \"Pressure Vessels\". Calculation of external pressure length for the first item: Spherical shape: 2400/2/3X2+3200 ； Elliptical shape: 2400/4/3X2+3200. 2. Comments: Tests the concept of stress concentration. 3. Comments: Basic knowledge on pressure vessel manufacturing. Errors in this question often arise from confusing \"heat treatment to restore mechanical properties\" with \"heat treatment to improve mechanical properties\"; in fact, these two types of heat treatment serve different purposes.