| dbo:abstract
|
- معامل المرونة النوعي هي خاصية في المواد تتكون من معامل المرونة لكل كثافة كتلة من المادة. معامل المروني النوعي هو مهم دائما في حيث فيها يتطلب أكبر قوة لاقل وزن. يثبت ان وحدته مربع وحدة المسافة لكل مربع وحدة الزمن. خاصية متعلقة به هي ، جزء أكبر تعميما يقارن بين أي وحدة قوة (ليس فقط معامل المرونة) إلى كثافتها. أعضاء حددوا لكى تكون سبيكة من الليثيوم والالمونيوم لهذه الخاصية، بين الباقي. (ar)
- Die spezifische Steifigkeit ist eine Materialeigenschaft, die als Auswahlkriterium im Leichtbau eine Rolle spielt. Sie gibt den Widerstand eines Werkstoffes mit gegebener Masse gegen Verformung im elastischen Bereich an. In vielen Fällen ist eine möglichst große spezifische Steifigkeit erwünscht. Die spezifische Steifigkeit lässt sich berechnen als Dabei ist die Dichte des Materials und der Elastizitätsmodul des betrachteten Materials. Die spezifische Steifigkeit ist eine maßgebliche Größe bei der Beschreibung der Schallgeschwindigkeit in Festkörpern. Für die Ausbreitung von Longitudinalwellen im langen Stab z. B. gilt: (de)
- Specific modulus is a materials property consisting of the elastic modulus per mass density of a material. It is also known as the stiffness to weight ratio or specific stiffness. High specific modulus materials find wide application in aerospace applications where minimum structural weight is required. The dimensional analysis yields units of distance squared per time squared. The equation can be written as: where is the elastic modulus and is the density. The utility of specific modulus is to find materials which will produce structures with minimum weight, when the primary design limitation is deflection or physical deformation, rather than load at breaking—this is also known as a "stiffness-driven" structure. Many common structures are stiffness-driven over much of their use, such as airplane wings, bridges, masts, and bicycle frames. To emphasize the point, consider the issue of choosing a material for building an airplane. Aluminum seems obvious because it is "lighter" than steel, but steel is stronger than aluminum, so one could imagine using thinner steel components to save weight without sacrificing (tensile) strength. The problem with this idea is that there would be a significant sacrifice of stiffness, allowing, e.g., wings to flex unacceptably. Because it is stiffness, not tensile strength, that drives this kind of decision for airplanes, we say that they are stiffness-driven. The connection details of such structures may be more sensitive to strength (rather than stiffness) issues due to effects of stress risers. Specific modulus is not to be confused with specific strength, a term that compares strength to density. (en)
- 比模量是單位密度的彈性模量，是一種材料性質。又稱勁度－質量比或比勁度。比模量高的材料在航天工業中有廣泛應用，這個領域需要把質量降至最低。從因次分析可得，比模量的單位為距離的平方除以時間的平方。 (zh)
|
