This book reports on original theoretical and experimental findings related to a number of cutting-edge topics in mechanics and mechanical engineering, such as structure modelling and computation; design methodology and manufacturing processes; mechanical behaviour of materials; fluid mechanics and energy; and heat and mass transfer. It includes a selection of papers presented at the 4th Tunisian Congress on Mechanics, CoTuMe'2018, held in Hammamet, Tunisia, on October 13-15, 2018. Thanks to the good balance of theory and practical findings, it offers a timely snapshot for researchers and industrial communities alike, and a platform to facilitate communication and collaboration between the two groups.