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Linear and non linear instability analysis of steel plate using ansysBY Priya .s. jain Under the guidance of Mr. Prashant sunagar.

Contents.IntroductionObjective Work completed Future work References Steel plate Advantages of steel

Uses

Importance of study Objective Buckling and post buckling analysis of thin steel plate under different boundary conditions subjected to Uniaxial compression Biaxial comprsssion shear

Work done so farLiterature review

Familiarizing with the use of finite element software ansys.11 1. solving beam and truss problems as basics 2. static analysis of plates 3. buckling analysis of plates

Excel sheet for calculating the eulers buckling co-efficient.

Fixing the dimensions of plate so as to arrive at desired buckling co-efficient. BUCKLING ANALYSIS OF PLATESCASE 1:SIMPLY SUPPORTED

BOUNDARY CONDITIONS , LOAD APPLICATION, AND OUT OF PLANE DEFORMATION (BUCKLING)

BUCKLING LOAD FACTOR

BUCKLING LOAD FACTOR FOR FIRST MODE 740.779 N/mmBUCKLING COEFFICIENT FOR SIMPLY SUPPORTED CASE, FROM THE LINEAR BUCKLING ANALYSIS (EIGEN BUCKLING ANALYSIS), THE BUCKLING LOAD OBTAINED FOR SIMPLY SUPPORTED CASE IS 740.779N/mm. CORRESPONDING CRITICAL BUCKLING STRESS IS ,=740.779N/mm/THICKNESS OF PLATE=740.779N/mm/10mm=74.0779N/mm2Buckling co-efficient

CONTDFROM THE STANDARD RELATIONSHIP, THE BUCKLING COEFICIENT,

K=(SCR *12(1-0.3^2)*B^2)/(t^2*PI()^2*E) =(74.0779*12(1-0.3^2)*1000^2)/(10^2*3.142*3.142*206.84E3) =4.099

Percentage errorDesired value of k = 4(from literature )Theory of elastic stability by timoshenko and gereObtained value of k = 4.099 ( from ansys for b/t = 100) . i.e. b=1000 and t=10 mm.% error = (4.099-4)/4 * 100 = 2.475%CASE II-ONE EDGE SS & OTHER EDGE FIXED I

BUCKLING COEFFICIENT FOR ONE EDGE SIMPLY SUPPORTED CASE& OTHER EDGE FIXED, From the linear buckling analysis(eigen buckling analysis), the buckling load obtained for this case is 1088 N/mm.Corresponding value for critical stress is,=1088N/mm/THICKNESS OF PLATE=1088N/mm/10mm=108.8N/mm2Buckling co-efficient

Percentage errorDesired value of k = 5.42(from literature )Theory of elastic stability by timoshenko and gereObtained value of k = 6.019 ( from ansys for b/t = 100) . i.e. b=1000 and t=10 mm.% error = (6.019-5.42)/5.42 * 100 = 11.05%Case III Fixed Fixed

BUCKLING COEFFICIENT FOR BOTH EDGES FIXED, From the linear buckling analysis(eigen buckling analysis), the buckling load obtained for this case is 1385 N/mm.Corresponding value for critical stress is,=1385 N/mm/THICKNESS OF PLATE=1385 N/mm/10mm=138.5N/mm2Buckling co-efficient.

Percentage errorDesired value of k = 6.97(from literature )Theory of elastic stability by timoshenko and gereObtained value of k =7.663 ( from ansys for b/t = 100) . i.e. b=1000 and t=10 mm.% error = (7.663-6.97)/6.97 * 100 = 9.94%Case IV fixed free

BUCKLING COEFFICIENT FOR ONE EDGE FIXED AND ONE EDGE FREE, From the linear buckling analysis(eigen buckling analysis), the buckling load obtained for this case is 295.014N/mm.Corresponding value for critical stress is,=295.014N/mm/THICKNESS OF PLATE=295.014 N/mm/10mm=29.5 N/mm2Buckling co-efficient.

Percentage errorDesired value of k = 1.7(from literature )Theory of elastic stability by timoshenko and gereObtained value of k =1.633 ( from ansys for b/t = 100) . i.e. b=1000 and t=10 mm.% error = (1.7-1.633)/1.7* 100 = 3.94%Case V free free

BUCKLING COEFFICIENT BOTH EDGES FREE, From the linear buckling analysis(eigen buckling analysis), the buckling load obtained for this case is 171.95 N/mm.Corresponding value for critical stress is,=171.95 N/mm/THICKNESS OF PLATE=171.95 N/mm/10mm= 17.195 N/mm2Buckling co-efficient

Percentage errorDesired value of k = 1(from literature )Theory of elastic stability by timoshenko and gereObtained value of k =0.952 ( from ansys for b/t = 100) . i.e. b=1000 and t=10 mm.% error = (1 -0.952 )/1* 100 = 4.8%Future workReferences. Astaneh-Asl, A., 2001, Seismic Behaviour and Design of Steel Shear Walls. Steel TIPS Report, Structural Steel Educational Council, July, Moraga, CA. Caccese, V., Elgaaly, M. and Chen, R., 1993, Experimental Study of Thin Steel-Plate Shear Walls Under Cyclic Load. Journal of Structural Engineering, ASCE, Vol. 119, No. 2, February, pp. 573-587

Celebi, M., 1997, Response of Olive View Hospital to Northridge and Whittier Earthquakes. Journal of Structural Engineering, ASCE, Vol. 123,No.4, April, pp. 389-396

Mimura, H. and Akiyana, H., 1977, Load-Deflection Relationship of Earthquake-Resistant Steel Shear Walls With a Developed Diagonal Tension Field. Transactions, Architectural Institute of Japan, 260, October, pp. 109-114 (in Japanese).Thank you