# Impact of Wind on the Movement of the Load Carried by Rotary Crane
## 1 Introduction  
The truck crane is currently one of the most important modes of equipment transport used to enable handling and assembly. Technological development and the increase of computational capabilities of computers allows comprehensive analysis of a modelling problem, which has a crucial impact on the design stage of new structures or during modification of existing objects. The literature on the subject lists a series of works pertaining to the problem of modelling crane dynamics; optimization of their work cycles; or influence of external forces. The problem of crane dynamics with the inclusion of various load transportation processes was presented in Works [1; 2; 3]. Paper [1] presents a dynamic model of a mobile crane and a carried load in which the flexibility of the support system was taken into account. The impact of the support system model on mobile crane stability was also analyzed. Paper [2] deals with the problem of dynamic analysis of a rotary crane with a description of all work stages (i.e., lifting, transport, and reloading of load). In addition, the article provides the mechanical-mathematical model with the use of [PERSON]'s equation of the second order. In Work [3], the theoretical and computational model of a forest crane and carried loads was presented. The numerical program, which has been developed in this work, allows analysis of load motion resulting from a crane's operating mechanism. The simulation model of a crane with the assurance of its stability was considered in Works [4; 5; 6; 7]. Paper [4] presents a stability assessment method of a truck crane's handling system and trajectory optimization process where safety indicator values were accepted as the criterion. Article [5] deals with the determination of a truck crane's outrigger reaction and stability factor monitoring during lift operations. In Paper [6], the mathematical model of the control system for a mobile crane waspresented. Numerical analyses with multiple strategies of rotational motion control and different types of controllers were also conducted. Moreover, the experimental results were discussed. The inherent stability of nonslewing articulated mobile cranes (NSAM) was analyzed in Work [7]. Different configurations and design geometry of the NSAM were checked. Papers [8; 9] present a dynamic analysis of particular elements of a mobile crane [8] and a harbor crane [9] together with the damping of those systems. Work [9] also performs a sensitivity analysis by tornado diagram and fast nonlinear analysis of container cranes. The influence of external forces, having impact on load-carrying systems was analyzed, inter alia, in Works [10; 11; 12]. In Paper [11], wind power impact on a container crane located in atmospheric boundary layers was considered, where wind power was measured with the use of a seven-component balance with different wind directions. The problem of positioning, work cycle optimization, and development of monitoring systems for a carried load were presented in Papers [6; 13; 14; 15; 16; 17; 18]. In the optimization process, new technological approaches were used (i.e., LiDAR scanner [13], three-dimensional (3D) visualization [15], or fuzzy-set logic models [19]). The influence of crane component flexibilities was also analyzed in Works [16; 17].  
This work presents a dynamic model of the system: truck crane--carried load. Dynamic problems were considered concerning two coupled planes of movement (lifting and rotation) with the inclusion of kinematic dependencies of the real system.