含裂縫與強制位移的靜不定配管系之塑性崩潰與殘存壽命解析

Plastic Behavior and Remaining Life Analysis of Statically Indeterminate Pipe Structure with a Crack Subject to Forced Displacement

劉松柏(Sung-Po Liu)

《健行學報》 34卷2期 (2014/04) Pp. 45-61

摘要

本文是探討含裂縫之靜不定配管系，承受垂直地震力後的強制位移之塑性崩潰行為，以及估算當裂縫發生後，至完全斷裂為止所需的殘存壽命（時間）。採用極限解析與彈塑性破壞力學的綜合解析手法，使用簡易柔度與J積分的計算，針對材料的破壞韌性值JIC與裂縫進展抵抗dJ/da等等，影響配管系的結構破壞因子進行分析，以期瞭解塑性鉸形成的情形，裂縫部位的回轉角、位移及裂縫夾角等關係。藉由計算例題，數值解析後描繪成圖，將能瞭解裂縫進展的情形，dJ/da值的大小明顯地影響裂縫部位的回轉角、位移及裂縫夾角遞增的情形，進而利用這些資料來解析裂縫進展之壽命評估。本文可提供建構劣化配管的健全性評估，以及提高電廠的配管結構可靠度之基礎。

關鍵字

破斷前洩漏 ； 塑性崩潰行為 ； 靜不定管結構 ； 殘存壽命 ； 彈塑性破壞力學

並列摘要

This report studies the statically indeterminate pipe structure with a crack, the plastic collapse behavior of the forced displacement after bearing the perpendicular seismic force, and estimates the remaining life needed (time) before the crack occurs.Based on the limit-analysis, analytical method of elastic-plastic fracture mechanics synthesis, and the computing of the simple compliance and J-integral, we are taking aim at the elastic-plastic fracture toughness value JIC of the material and crack extension resistance dJ/da, etc. that affect the structure fracture factor of the piping system progress analysis, the relationships such as rotational angle, displacement and crack angle, etc., in order to understand the situation of the plastic hinge forming with the period.From the computing examples, the numerical analysis described in the following charts can explain the situation that the crack makes in progress, the dimension that dJ/da clearly affect the rotational angle, displacement and crack angle, then make use of this data for the valuation of life of the analytical progress of crack. This report can provide the piping establishment with material for pipe structure reliability, to explore the inferior sound valuation that turns the foundation of the further stilted power plant piping structure.

並列關鍵字

leak-Before-Break ； plastic collapse behavior ； statically indeterminate structure ； remaining life ； elastic-plastic fracture mechanics