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This paper proposes a complex boundary wave superposition method with a unique solution of full wavenumber based on the similarity between the acoustic wave superposition method (WSM) and the external excitation response of dynamic systems and combined with the idea that a damping system has a unique solution in dynamic theory. By placing the virtual equivalent source on the virtual boundary of complex space, the conventional WSM acquires damping properties comparable to those of the dynamical system. This approach successfully addresses the non-uniqueness of the solution at the eigenfrequency and is more efficient than the conventional combined layer potential method. The paper presents a comprehensive description of the proposed method, with a focus on theory, modeling, and parameter selection. The effectiveness of this method is evaluated by applying it to two types of acoustic problems, namely, radiation and scattering. The numerical results indicate that this method effectively addresses the non-unique problems encountered in conventional WSM. Furthermore, the proposed method is as accurate and efficient as the conventional WSM. [ABSTRACT FROM AUTHOR]

With the increasing demand for teaching quality and personnel training of higher education in China, it has become the goal of application-oriented universities to cultivate high-quality composite application talents with innovative ability, practical ability and entrepreneurial spirit. Innovative professional practice teaching reform is an important way for higher education to better achieve the goal of talent training and improve teaching quality. Firstly, the necessity and significance of professional practice teaching reform is expounded in combination with the current situation of the mechanical engineering and education. Then, the content of teaching reform is explored in the light of the present practical teaching situation of mechanical engineering specialty. Finally, based on the current situation and development goals of the application-oriented universities, some safeguards measures are put forward to ensure the smooth development of practical teaching reform and achieve effective results.

A finite element model (FEM) of the bracket arm of wrecker is developed and the mechanical behavior under six representative conditions is studied in this paper. Stress test experiment is carried out to validate the presented FEM. Comparison analyses show that results predicted from the FEM are in good agreement with those obtained from the test experiment. Moreover, the mechanical behavior analyses also give the danger working conditions for each component of the bracket arm. Based on the stress distributions under the danger working condition, structural improvement is conducted for the component which is prone to material failure. Mechanical behavior analyses of the improved structures are also carried out in this paper. Numerical analysis results show that the maximum stresses of each improved component of the bracket arm are all reduced to close or below the allowable stress. This indicted that the load bearing capacities of each component are improved effectively and meet the requirements of engineering applications. [ABSTRACT FROM AUTHOR]

Mechanical behavior of the outriggers of wrecker is analyzed based on finite element method in this paper. According to actual working condition, detailed loading and boundary constraint are established by using analytical method. In order to validate the presented finite element model (FEM), stress test experiment is carried out and comparison analysis is also conducted. The maximum error value is smaller than 7.2%. This indicated that the proposed FEM has a good prediction accuracy which meets the engineering requirements. Mechanical behavior analysis shows that the outriggers have enough strength to bear the working load for the special wrecker analyzed in this paper. Moreover, effects of the material and location of sliders on the mechanical behavior of outriggers are also studied in this paper. Numerical analysis results show that the sliders play an important role in determining the bearing capacities of the outriggers and it should be considered detailedly in structure design process. [ABSTRACT FROM AUTHOR]