The rapid advancement of wireless charging systems (WCSs), fifth-generation (5G) technology, electric vehicles (EVs), and artificial intelligence (AI) systems result in a critical need for more efficient thermal management materials. h-BN, characterized by its ultra-high theoretical thermal conductivity and excellent electrically insulating properties, serves as a promising filler for blending with polymers to develop high-performance thermally conductive composites. However, it is still a challenge to attain a high through-plane thermal conductivity of over 40 Wm⁻¹ K⁻¹ at filler content at 80 vol%. This persistent limitation is mainly attributed to the fact that most current h-BN used in the manufacture of thermal conductive composites has relatively smaller lateral size (below 40 µm). Additionally, the effective orientation strategy (e.g., ice-template strategy) usually results in difficulties in mass production. Here, a two-step process involving blade coating and lamination is used to prepare BN/TPU composites with an through-plane thermal conductivity of 43 Wm⁻¹ K⁻¹ at h-BN content of 67 vol%. With upper-level electric insulating properties and wave-transparent characteristic, the multifunctional BN/TPU composite shows excellent thermal management ability in the high-power wireless charging area and also has the potential to be used in the 5G communication technology field.

In recent years, the topic of progressive structural collapse has received more attention around the world, and the study of element importance is the key to studying progressive collapse resistance. However, there are many elements in truss structures, making it difficult to predict their importance. The global stiffness matrix contains the specific information of the structure and singularity of the matrix can reflect the safety status of the structure, so it is useful to evaluate the key elements based on the global stiffness matrix for truss structures. In this paper, according to the tangent stiffness-based method for the element importance, the square pyramid grid was chosen as an example, and the distribution rules of key elements under different support conditions, stiffness distributions, and geometric parameters were studied. Then, three common symmetric grid forms, i.e., diagonal square pyramid grids, biorthogonal lattice grids, and biorthogonal diagonal lattice grids, were selected to investigate their importance indices of elements. The principle in this work can be utilized in progressive collapse analysis and safety assessment for spatial truss structures.

Robustness and vulnerability are important evaluation criteria for structural safety to improve progressive collapse resistance. Modeling rapid evaluation on important elements in the conceptual analysis stage is an essential and efficient way to ensure the robustness of a design. This paper proposes an evaluation method for element importance by using structural strain energy, which can reflect the influence of geometric topology and external load distribution on the structural safety status simultaneously. Three simple planar trusses are chosen to clarify the proposed method. Moreover, the influences of geometric topology, boundary condition, stiffness distribution and load distribution on the element importance are investigated. This evaluation method also extends to the two spatial truss structures, regular quadrangular pyramid grid structures and chessboard-shaped pyramid grid structures. The distribution characteristics of important elements are obtained. This work defines the element importance distribution law of typical structures. It provides a method for rapid robustness analysis of general truss structures, which can be effectively integrated into the existing analysis platform.

The seismic or static undrained slip line field theory and Cauchy, Riemann, mixed boundary value problems for undrained soil slopes are derived. A new failure mechanism is proposed to determine the undrained bearing capacity adjacent to slopes. The effects of geometric or strength parameters and seismic forces on static and seismic undrained bearing capacity are investigated. The convergence of the proposed method is proved. The static and seismic undrained bearing capacities predicted by the proposed method are close to those of the currently existing methods. The proposed method does not need to assume or search the failure modes, and a new limit state evaluation index is given.