One of the most important problems in the design procedure of space structures is how to get rational shapes of freeform surfaces. Based on the concept of structural morphology, the fabrication of freeform surfaces can be combined to the method of pursuing optimal structures with rational mechanical performance, which can be defined as computational morphogenesis. In this paper, some concepts of structural morphology are introduced and some key problems are discussed simultaneously.The key problems can be abstracted as follows:Firstly, how to fabricate freeform surfaces?Secondly, what kind of generating methods are feasible for rational freeform structures. By discussing the questions above, some advices are proposed finally.

In this paper, the superiorities of 3D finite element graphics system developed by OpenGL, such as high speed, powerful drawing function, convenient selection and feedback and nice visual effect are demonsrated through the comparison between GDI and OpenGL, which are both popular in graphics system at present. The paper also introduces drawing process of 3D model by OpenGL, display technology of concave polygon, back face culling and alpha blending, real-time rotation, translation, scaling, and efficient capture algorithm of PKPM-SAUSAGE software as well as the results display smoothing technology and color correction technology by shader programming in post-processing. Finally, the efficiency of OpenGL graphics display, rotation, translation, scaling and capture in PKPM-SAUSAGE software is verified by practical engineering examples.

To make up for the deficiencies of Rayleigh damping and "simplified" modal damping in explicit dynamic analysis, this paper proposes the "correction" modal damping (M-M D) of modal damping and mass damping based on high-precision finite element model. It also analyzes Rayleigh damping and M-M D from the perspective of explicit solving accuracy, stability and inhibiting effect on high-order modal amplifier response. The paper uses PKPM-SAUSAGE to compare the explicit dynamic time calculation results of these two dampings and analyzes the effect of high-order modal amplifier response on structural dynamic analysis and the inhibiting effect of these two damping models on high-order modal amplifier response. The results show that M-M D excels.

Firstly, solving methods for dynamic analysis are introduced, which can be largely classified into explicit integration method and implicit integration method, and their advantages and disadvantages are also introduced. Secondly, the simulation method of beam element, column element, shear wall element and slab element in PKPM-SAUSAGE are introduced.Because of the small integration time step and detailed modeling, the amount of calculation will be increased largely."CPU+ GPU" parallel computing technology is used in PKPM-SAUSAGE, and the mesh quality of model is also optimized, which improves the efficiency of dynamic elastoplastic analysis.