Plastic design of steel beams and frames has been included in building codes since
1948 in Great Britain and since 1959 in the United States. The increased use of plastic design
and the present trend toward applying its methods to reinforced and prestressed concrete
indicate that the basic advantages of plastic analysis - accurate estimate of the collapse load,
simplicity of application, and economy of structure - are more and more appreciated b'v
practicing engineers. Codes on reinforced concrete slabs (European Conuuittee for Concrete)
and on pressure vessels (ASME) are on the way to adopt plastic limit state as one of the
design criterions. Hence, it was felt urgent to provide all interested people with a ~'nthesis
work on the subject.