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.