Spontaneous imbibition is a natural phenomenon in porous media extensively occurring in many fields of engineering applications and natural sciences. Thus, the issues on the basic statistics and kinetics of spontaneous imbibition in porous media have become one of hot topics for many years. In this review, progresses in traditionally theoretical researches on Lucas-Washburn (LW) model, Terzaghi model, Handy model, Mattax and Kyte scaled model of dimensionless time, Aronofsky scaled model of normalized recovery and recent advances in the area especially over the last decade are reviewed, including criterion parameters for analyzing the mechanisms of spontaneous imbibition and recent studies on spontaneous imbibition in porous media based on the fractal theory. Brief reviews on numerical simulations and experiments about the influence of factors on the imbibition rate are also addressed. A few of comments are also made on the future research directions and subjects on spontaneous imbibition of Newtonian and non-Newtonian fluids in porous media and fractured porous media with dual-porosity based on the fractal theory and numerical simulations.

Isogeometric analysis (IGA) is a current trend in engineering analysis that is likely to leave a significantly impact on Computer-Aided Engineering (CAE). The basic idea of IGA is to utilize CAD geometry to facilitate analysis. This seemingly simple change of geometric language eliminates many bottle-neck issues that plagued CAE for years, and opens a pathway for a tighter integration of design, analysis, and optimization. In this review paper, the background, theory, advantages, and applications of isogeometric analysis are discussed. Topics of algorithmic development, including NURBS bases, T-spline bases, unstructured meshes, efficient quadrature methods, trimmed surface technologies, refinements and so on are reviewed. Recent advances of IGA in shell problems, large deformation, fluid-structure interaction, structural optimization, contact problems, biomechanics, thermal analysis, and electromagnetics are also summarized.

In this paper, modern structural performance simulation or experimentation systems can be classified into global (i.e. structure) and local (substructure) categories. The background, some basic concepts, state-of-the-art development and applications of hybrid simulation (experimentation) are discussed in detail within this kind of classification. Based on the object-oriented finite element program Open System for Earthquake Engineering Simulation (OpenSees) and its high-level software architecture as well as parallel computing program structure, four OpenSees-based hybrid simulation and hybrid experimentation systems are addressed. Further, a brief introduction of the concepts and applications of multi-scale integrated hybrid modeling is given herein. It has been proved to be feasible for developing hybrid simulations or hybrid experimentations based on some commercially and non-commercially available finite element (FE) software platforms. The key issue confronted is how to incorporate different FE software platforms with the testing apparatus locating at different places and to make them work in a precisely synchronized mode. Hybrid simulation technology has some advantages over other conventional analytical methods, especially for the case of progress collapse simulation of structures subjected to severe earthquakes. However, as critically pointed out in this paper, substantial development of this novel technology cannot be achieved without seamless fusion of multi-disciplinary that should be stressed right now.