A SEMI-ANALYTIC METHOD FOR BENDING OF ANGLE-PLY LAMINATES

The deflection of symmetric angle-ply laminated plates is expressed by a series which exactly satisifies the bending governing equation and,in a common simply connected region,can uniformly approximate any solution of the equation.The coefficients of the series are determined by the use of the boundary collocation method.For nonsymmetric laminates,if the reduced bending stiffness is introduced,the method can also be applied.A number of examples are presented in order to investigate the convergency of the deflection and the internal forces.For clamped round laminates,aeeurate results can be obtained by taking only 6 undetermined coefficients and 3 collocations.For simply supported ±45°angle-ply regular rhombic laminates,when 13 coefficients and 7 collocations are taken,the deviation of results from the double trigonometric series is very small.For simply supported square anisotropic plates,the difference between the results obtained by the isotropic skew plate analogy and those by the semi-analytic method with 13 coefficients and 10 collocations is less than 1.7%.For clamped ±45°square laminates for which no exact solution exists,the results are obtained by taking 13 coefficients and 7 collocations and by taking 33 coefficents and 25 collocations,and it is found that there is little differency between them.