12. Calculation formula of Young's modulus

12. Calculation formula of Young's modulus		Symbol description and unit
(1-1) Young's modulus	E=σ/ε　　　〔kgf/mm2〕 E=	σ： Tensile (compressive) stress　　　〔kgf/mm2〕
		ε： Strain in the stress direction
(1-2) Young's modulus	E=P*L/(A*L')　　　〔kgf/mm2〕 E=	P： Tensile (compressive) load〔kgf〕
		L : Initial length of material　〔mm〕
		A： Cross-sectional area　〔mm2〕
		L'：Length of expansion (tension) and contraction (compression)〔mm〕
(2)Strain in the stress direction	ε=L'/L ε=	L'： Length of expansion (tension) and contraction (compression)〔mm〕
		L：Initial length of material　〔mm〕
（a） Tension　　　　　　　　　　(b) compression		material	Young's modulus
		Mild steel Hard steel Cast steel cast iron Nickel steel Copper casting Copper rod and copper wire Phosphor bronze Gunmetal brass Monetal Duralumin Aluminum Nickel zinc lead Tin Gold Silver granite marble sandstone Andesite Concrete Red brick (burnt) Red brick (normal firing) Akamatsu black pine Cedar Japanese cypress Chestnut Shirakashi Nara Zelkova Kaede bamboo	20,500〜21,000 21,000 17,500〜21,600 7,500〜11,900 20,900 8,400〜9,000 10,500〜12,100 9,450〜10,500 8,050〜8,400 7,000〜10,000 17,500〜18,300 7,350 6,300〜7,500 20,000〜22,000 8,000〜13,000 1,500〜1,700 4,000〜5,500 7,000〜9,500 6,000〜8,000 5,000 3,100 1,700 1,150 2,400 2,100 930 570〜1,400 850 570〜1,300 770〜1,300 490〜1,100 760〜860 590〜1,100 840〜1,100 570〜860 990
Reference: "Machine Official Collection" (co-authored by Masaaki Oishi / Tatsuo Inami) Material Mechanics, page 45, Refer to Young's modulus. References: "Machine Design Handbook for Engineers" (Revised by Saburo Kano) Mechanical Properties Allowable Stress and Mechanical Properties of Materials Page 129 Quoted from the table of elastic modulus of materials.