Energy efficiency of timber construction joint with wooden screw

The topicality of studied subject is based on inappropriate usage of different materials in wooden structures, since using metal joint in wooden construction leads to reduction of construction working life cycle. In this regard, a study of several options for wooden screw carving was conducted in order to determine the most appropriate one (screw). There are several different types of carving, such as: trapezoidal, triangular, rectangular, etc. The most appropriate ones are trapezoidal and triangular-section threads for wooden screws. The effectiveness of a wooden screw thread was determined from the conditions (capacity) of shear fracture and bearing stress. After analyzing the results of calculations of the specific capacity for shear fracture and bearing stress, it can be concluded that the value of specific bearing capacity for shear fracture is less than the value of bearing stress by 1.3%. Therefore, a further comparison of the trapezoidal thread and the triangular cross-section will proceed from the spalling conditions. It has been found that the most effective thread is a triangular cross-section. Based on the results of calculations, a mathematical model has been established that describes the dependence of the carrying capacity on the screw diameter