The mechanical properties of steel bar are the most important performance of steel. The mechanical properties include tensile properties, impact properties and fatigue properties. Today let's take a look at these performance aspects in detail.

　　1、拉伸性能反映建筑鋼材拉伸性能的指標，包括屈服強度、抗拉強度和伸長率。屈服強度是結構設計中鋼材強度的取值依據。

　　1. Tensile properties reflect the tensile properties of building steel, including yield strength, tensile strength and elongation. Yield strength is the basis of steel strength in structural design.

　　2、沖擊性能是指鋼材抵抗沖擊荷載的能力。鋼的化學成分及冶煉、加工質量都對沖擊性能有明顯的影響。除此以外，鋼的沖擊性能受溫度的影響較大，沖擊性能隨溫度的下降而減小；當降到一定溫度范圍時，沖擊值急劇下降，從而可使鋼材出現脆性斷裂，這種性質稱為鋼的冷脆性，這時的溫度稱為脆性臨界溫度。脆性臨界溫度的數值愈低，鋼材的低溫沖擊性能愈好。所以，在負溫下使用的結構，應當選用脆性臨界溫度較使用溫度低的鋼材。

　　2. Impact performance refers to the ability of steel to resist impact load. The chemical composition, smelting and processing quality of the steel have obvious effects on the impact properties. In addition, the impact property of steel is greatly affected by temperature, and the impact property decreases with the decrease of temperature. When the impact value falls to a certain temperature range, the impact value decreases sharply, which can cause brittle fracture of steel. This property is called cold brittleness of steel, and the temperature at this time is called brittle critical temperature. The lower the critical brittle temperature is, the better the low temperature impact property of steel is. Therefore, the steel with lower brittle critical temperature should be selected for the structure used at negative temperature.

　　3、疲勞性能受交變荷載反復作用時，鋼材在應力遠低于其屈服強度的情況下突然發生脆性斷裂破壞的現象，稱為疲勞破壞，疲勞破壞是在地應力狀態下發生的，所以危害極大。往往造成災難性的事故，鋼材的疲勞極限與其抗拉強度有關，一般抗拉強度高，其疲勞極限也比較高。

　　3. When the fatigue performance is subjected to repeated alternating loads, brittle fracture occurs suddenly when the stress of steel is much lower than its yield strength, which is called fatigue failure. Fatigue failure occurs under the condition of in-situ stress, so it is harmful. It often causes disastrous accidents. The fatigue limit of steel is related to its tensile strength. Generally, the tensile strength is high and its fatigue limit is relatively high.

　　以上就是關于鋼筋力學性能的相關解說，后期我們會將供應性能方面的知識進行講解，有想要了解的人士可以多多關注一下:http://www.hubangjie2012.cn/

　　These are the explanations about the mechanical properties of reinforcing bars. Later, we will explain the knowledge of supply performance. Those who want to know can pay more attention to it: http://www.hubangjie2012.cn./