Tham khảo tài liệu 'mechanical tolerance stackup and analysis part 15', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 408 Chapter 20 Triangle 12 Solve For Y2 21 2s 2X X1 x2 80 328 Y2 328 80 Note Y1 is less than the full 2-mm value of the Flatness tolerance. With convex form error the vertical variation of the Datum Feature A surfaces is only at the centerline of the bolt holes. It is assumed that the bolt forces will pull the surfaces together along the CL of the bolts. Figure Form tolerances Like triangles projecting the rotation out to the side flanges. It will also be assumed that the parts deform in a uniform manner. The deformation between the point of contact on datum feature A and where the bolt forces are applied will cause the part features farther out to rotate uniformly as if that portion of the part were rigid. Figure shows the half-brace assembly after the bolts have been tightened. The axial loads have pulled the mating surfaces together and the side flanges have rotated inward a corresponding amount. As the mating surfaces of the half-braces are deformed they cause the edges of the interfacing surfaces and side flanges to rotate through an angle. It is relatively easy to calculate this angle and just as easy to determine the amount this rotation affects the holes in the side flanges. This problem will be solved in the same manner as in Chapter 15 which used like triangles to convert the rotation of one set of features into the linear translation of another set of features. Figure shows an enlarged detail view of the half-brace against datum feature simulator A. In this example datum feature A of each Form Tolerances in Tolerance Stackups 409 The Distance Between the Side Flange Hole was Reduced by mm on Both Parts. The Effect of the Positional Tolerance on the Holes is not included. Figure Form tolerances Brace assembly after loading with dimensions. half-brace may deviate mm which is the height of the form error at the bolt holes. Again it is assumed that when the bolts are tightened each surface will be
