Strength Design in Steel Using Programmable Calculators

During the past ten years, a gap has developed between large digital computers and manual computing methods. This is particularly true with regard to the analyses and design of structural members. The increasing availability of large computer systems and their associated software, coupled with a dramatic reduction in cost, has placed computer analysis capability well within reach of most structural engineering offices. Member forces can be readily determined using either special frame analysis programs or general purpose programs which are available on commercial computer systems. However, once the member design forces are determined, the engineer must revert to hand calculations for determining and checking the design of the individual members. These calculations can become monotonous and time consuming for a structure of even modest size. Furthermore, such calculations tend to become inaccurate and insufficient. For example, a designer may accept a given section as adequate without trying other possibilities which may lead to a more efficient design. This paper has illustrated the use of a hand-held programmable calculator for the strength design of steel frames. Although the process is only semi-automatic, it still saves the designer from having to perform the rather mundane calculations involved with member selection and checking. Its main attraction is the low cost and ready availability of the calculators, plus the fact that the calculation can be done at the designers desk without extensive data preparation. The procedures assume that the design forces are known. Therefore, a force analysis will have to be done on a larger computer system. It should also be noted that the use of this type of design procedure allows complete interaction of the engineer with this design process. Therefore, engineering judgment decisions can be made and incorporated in the design as it progresses.