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ultimate stress 極限應力,極限脅強。

ultimate yield

Ultimate stress increment is a hotspot problem in theory of unbonded partially prestressed concrete structure , however , according to design critera and the art of the state on this issue around the world , it is still not considered in reason that ultimate stress of unbonded tendons in prestressed concrete multi - span continuous structures varies with load cases 無粘結筋的極限應力增量一直是無粘結預應力混凝土結構理論中熱點問題,而從目前各國的設計依據及研究現狀來看,還沒有合理考慮多跨連續結構的無粘結筋極限應力隨荷載工況變化的情況。

The study in the paper starts with beam distortions , and it treats the plastic deformation area as pure bending sect , rest of the beam as rigid bodies . according to different shapes of the external tendons , it divides into three structural forms familiar in projects , that is the beams with no deviator , with a deviator and with two deviators , and studies the relation between the deformation of the external prestressing tendons and that of the beams , and derives the formulas of the ultimate stress increment of external tendons . in the formulas , the ultimate angle corresponding to half of the plastic deformation area is considered as a variable parameter 本文首先從梁極限狀態下的變形入手,將塑性鉸區看作純彎段,將塑性鉸以外的區域看作剛體,按照體外預應力筋的形狀不同,分工程中最常見的三種體外結構形式,即無轉向塊的直線型體外筋混凝土梁、具有一個轉向塊的單折線型梁和具有兩個轉向塊的雙折線型梁,研究體外預應力筋變形和梁體的變形間的關系,推導出以極限狀態下塑性鉸區之半對應的轉角為參數的計算體外預應力混凝土簡支梁以及連續梁的體外筋應力增量計算公式,并進一步求得梁的極限承載力。

This thesis briefly analyzes some yield criteria and instability criteria to the sheet metal forming first . then according to the transformation rule from ultimate strain to ultimate stress , it establishes the mathematical calculation models of the forming limit stress diagram for the software development according to hill48 、 hill79 and hosford yield criterion irrespectively 本文首先分析了板料成形的屈服準則和失穩準則,然后根據極限應變到極限應力的轉換關系,分別采用hill48屈服準則、 hill79屈服準則和hosford屈服準則,建立了用于軟件開發的成形極限應力圖的數學計算模型。

This paper demonstrates ultimate stress increment of unbonded tendons can be composed of approximate elastic deformation along the elements and local plastic deformation by nonlinear analysis on the unbonded partially prestressed concrete continuous structures . referring to the rule of ultimate stress increment of unbonded tendons at every load case , a regression formula of ultimate stress increment of unbonded tendons based on elastic - perfectly plastic model has been presented for engineers to calculate ultimate stresses of unbonded tendons in prestressed concrete multi - span continuous structures 考慮在各種荷載工況作用下無粘結筋極限應力增量的變化規律,并與理想的彈塑性模型相比較,最終得出以理想彈塑性模型計算各種荷載工況作用下無粘結筋極限應力增量的回歸公式,從而為預應力混凝土多跨連續結構的無粘結筋應力設計計算提供有益的參考。

At last , the effect of the steel yield strenth , the yield - to - ultimate stress ratio , the shape and size of the access hole is researched . in conclusion , the finite - elenent model and the program adoped in this paper can well similate the response of beam - to - cloumn connections uder cyclic load 本文所建立的模型及采用的程序能夠很好的模擬、研究在循環荷載作用下剛性梁柱連接的反應,為進一步研究剛性鋼框架梁柱連接的抗震性能打下了基礎。

An important step in structure design is the calculation of the ultimate flexural strength of external prestressed concrete beams , which needs to calculate the ultimate stress increment of external tendons first 結構設計的一個重要環節就是極限承載力計算,而計算體外預應力混凝土梁的極限承載力就必須求得梁在破壞時的體外筋應力增量。

Measures in force per unit area [ i . e . pounds per square inch ( psi ) ] the ultimate stress that can be withstood by a material in tension prior to failure 在出現問題前材料單位面積所能承受的極限拉力,例如:磅每平方英寸( psi ) 。

Relations between the fractal dimensions of tensile fractures and the tensile ultimate stresses for the grain composite material caco3 abs 拉伸斷口表面分形維數與其拉伸強度極限的關系

Calculation methods for the ultimate stress and effective height of external prestressing tendons 體外預應力筋極限應力和有效高度計算方法