Latin American Journal of Solids and Structures

Modular cross-laminated timber (CLT) construction offers rapid, low-carbon housing, yet its seismic viability is governed by connection performance. This PRISMA-based systematic review analyzes 50 publications on connection technologies for volumetric CLT, addressing the complete load path—Intra-Module (InMC), Inter-Module (IMC), and Module-to-Foundation Connections (MFC)—rather than inter-modular connections alone. The synthesis is organized around four questions: the state of development and functional classification of connections; their mechanical performance and seismic suitability; the trade-offs between circularity and reusability; and the main knowledge gaps. Adhesive-free, timber-only interlocking joints support material circularity but dissipate energy through irreversible timber crushing and splitting, so their cyclic ductility is limited and non-repeatable. Hybrid steel–timber systems and friction dampers instead concentrate inelastic demand in replaceable metallic or frictional components, delivering the stable, repeatable hysteresis and post-event reusability required in high-seismic regions. The field remains fragmented, with gaps in full-scale validation, durability (corrosion, preload relaxation, fatigue), and multi-directional modeling, and performance data biased toward moderate-seismicity codes. We advocate a “strong fastener–weak connector” philosophy, supported by capacity-design and stiffness-compatibility guidelines that treat InMC, IMC, and MFC as one load-path system, enabling standardized, resilient, and reusable modular CLT structures.

Silicon carbide (SiC) ceramics have been widely used in lightweight armor protection due to their combination of high compressive strength, high hardness, and low density. The mechanical properties and penetration resistance of SiC ceramics are of significant importance for armor protection design. To investigate the mechanical response and fragment penetration resistance of SiC ceramics, this study systematically carried out plate impact tests, dynamic and quasi-static uniaxial compression tests, as well as ballistic penetration tests. Based on the experimental data, the parameters of the Johnson-Holmquist II (JH-2) constitutive model for the SiC ceramic were calibrated. Subsequently, a numerical simulation model of tungsten alloy fragment penetration into SiC ceramic composite targets was established. The model was validated using tungsten alloy fragment penetration tests on SiC/6061-T6 composite targets, and the penetration characteristics of fragments into SiC/6061-T6 composite targets were systematically compared with those into monolithic 6061-T6 aluminum alloy targets. The error between the experimental and simulation results of the composite target penetration tests is less than 9%, verifying the accuracy of the calibrated JH-2 model parameters. For monolithic 6061-T6 aluminum alloy targets, the penetration depth of spherical fragments is significantly greater than that of cubic and cylindrical fragments. In contrast, for the ceramic composite targets, the residual penetration depth of spherical fragments is markedly lower, indicating that SiC ceramic exhibits substantially better resistance to spherical fragments than to the other two fragment shapes. This study can provide a theoretical basis and data support for the design and performance evaluation of lightweight armor protection.

In commercial aviation, even incremental improvements in aircraft performance can yield substantial environmental benefits. Increasing wingspan is a proven strategy to enhance aerodynamic efficiency and reduce emissions, but practical limitations arise as many airports cannot accommodate larger-wing aircraft. Folding wingtips have emerged as an innovative solution to reconcile efficiency gains with operational flexibility. However, analyzing such adaptive structures requires addressing geometric nonlinearities induced by large displacements, which traditional linear models fail to capture accurately. This study proposes a computationally efficient framework for static and dynamic analysis of highly flexible structures, including folding wingtips. The method combines a linear structural model based on the Rayleigh-Ritz method with flexible multibody dynamics, where geometric nonlinearities are modeled through rigid connections between multiple flexible bodies. This hybrid approach avoids the high computational costs of fully nonlinear structural models while retaining fidelity in capturing nonlinear dynamic behavior. Results demonstrate that the framework accurately predicts the structural dynamics of highly flexible structures with folding parts, validating its capability to handle complex, morphing geometries. The proposed methodology not only supports the design of next-generation adaptive wings but also offers versatility for broader applications in aerospace engineering, where flexibility and large deformations play a critical role.

Abstract

This study evaluates and improves models for predicting the high-velocity penetration response of ultra-high-performance concrete (UHPC) used in protective structures. The research scope involves systematically comparing three common concrete constitutive models: Holmquist–Johnson–Cook (HJC), Riedel–Hiermaier–Thoma (RHT), and Karagozian & Case (K&C). First, the models' theoretical differences regarding strain-rate effects and tension-compression asymmetry were analyzed. Next, their material parameters were calibrated using fundamental mechanical tests and literature data. An LS-DYNA finite element model was then established and validated against ballistic experiments (633-959m/s) by evaluating penetration depth, surface crater morphology, and internal damage evolution. The results indicate that the HJC model is the optimal choice for high-velocity penetration simulations. It yielded the lowest average depth error (-11.89%), and its localized damage pattern best matched UHPC's high-strength and high-toughness traits. In contrast, the RHT model caused premature matrix softening under high hydrostatic pressure, leading to a -21.76% error. The K&C model overpredicted surface funnel-shaped crater damage, with its penetration depth error increasing to -26.34% at high velocities. Furthermore, extended simulations at 800–1500 m/s revealed that the traditional Forrestal analytical model deviates significantly in the ultra-high-velocity regime. To solve this, a modified analytical model tailored for UHPC was developed. By accounting for dynamic yield and high-pressure shear rheological softening mechanisms, the new model introduces a dynamic strengthening coefficient and a rheological softening factor. Ballistic validation demonstrates that the theoretical predictions of this modified model match experimental data well, with a maximum relative error of 14.54%. Overall, this research provides vital numerical model selection and theoretical support for designing and evaluating UHPC protective structures against kinetic energy projectile impacts.

This study examines the damage effects of an internal explosion in an underwater thin-walled steel box on neighboring cabin structures by integrating experimental investigations of a three-cabin steel box with numerical modeling. The study analyzes the propagation behavior, dynamic response, and resulting damage effects of explosion loads originating in the central cabin and acting on adjacent cabins. The results show that the pressure history in the adjacent cabin displays multiple peaks along with an extended positive pressure phase, arising from the combined action of the shock wave transmitted through the internal bulkhead from the central cabin and the reflected waves generated in the adjacent cabin. The expansion and contraction processes of the explosion bubble are largely confined to the central cabin where the charge is located, or the bubble escapes through ruptured structural regions. In cases where no perforation exists in the separating internal plate, the bubble typically does not penetrate the adjacent cabin. Under internal explosion loading conditions, the deformation and fracture of bulkhead plates in the adjacent cabin are primarily induced by the transmission of bubble expansion effects into that cabin. Furthermore, with an increasing explosive charge mass in the central cabin, the damage mode of the adjacent cabin gradually evolves from plastic deformation to edge cracking and shear failure, while an increase in wall thickness effectively reduces the overall extent of structural damage.