This textbook in structural mechanics is based on the methodology of the finite element method. The understanding of basic elements of structural mechanics, springs, bars, beams and foundations, is gradually built up in one, two and three dimensions. Using these elements it is shown how complex load bearing structures can be modelled and analysed. Methods for linear as well as geometric and material nonlinear analysis are presented.  In order to highlight the generality of the described methodology a short section that addresses other areas of applied mechanics such as thermal conduction, moisture diffusion and groundwater flow is included. Structural Mechanics: Modelling and Analysis of Frames and Trussesis an idealtextbook for undergraduate students. Computer programs that support the book can be freely downloaded from the website www.structarch.org.