关键词: compliant assembly, residual stress, assembly deformation, finite element analysis (FEA)

Abstract:

The process of low-velocity water entry is utilized on a large scale for the military and engineering purposes. However, there are rarely systematic experimental investigations into the low-velocity water entry of cylinder structure for reference. In order to obtain typical phenomena and relevant laws, we design a set of experimental facilities with adjustable parameters and better repeatability to study this process with a high-speed photography system. The influences of cylinder radius, initial velocity and entry angle on the process of low-velocity water entry are tested. Results show that six typical phases exist in this process: structure submersion, necking, cavity formation, cavity abscission, spray at the free surface and jet formation. Three factors mentioned above are key parameters and influence the process in different degrees, and some laws obtained in this paper have a reasonable agreement with the theoretical results. Our results provide references for the relevant numerical researches and engineering applications.

Key words: laterally loaded piles, hydraulic head, land deformation, pumping-recovery, $m$-method, back analysis, horizontal displacement, outage performance, heterogeneous circumstance, magnetic resonance imaging (MRI), sparse representation, non-convex, generalized thresholding, amplify-and-forward (AF), beamforming, channel state information (CSI), power control, cognitive radio, monotone optimization, price, Stackelberg game, fairness, supply chain coordination, dictionary updating, alternating direction method, two-level Bregman method with dictionary updating (TBMDU), circular excavation, heterogeneity, substitution, service parts, last stock, admission control scheme, handover service, high-speed train communication, S-clay1 model, undrained compression test, functionally graded materials, low-velocity water entry, cylindrical sandwich panel, rectangular sandwich plate, simply supported, free vibration, supercavitating, ventilated, dynamic mesh, pitching, resting-state brain function network, model network, connection distance minimization, topological property, anatomical distance, wall effect, underwater glider, nonlinear control, adaptive backstepping, Lyapunov function, cylinder structure, cylinder radius, initial velocity, entry angle, soft soil, strain-dependent modulus, common neighbor, video capsule endoscopy (VCE), frame rate, working hours, in vivo experiment