Multi-skeleton model for top-down design of complex products

Abstract

Generally, there are two alternative design approaches available to engineers: bottom-up and top-down. Considering the sharp increase in the complexity of most mechanical products, the top-down design approach is more widely adopted in the development of complex products. However, in traditional top-down design process, design parameters are communicated through single-skeleton models, and design units are strongly coupled due to the multi-dimensional complexity of products. Toward this end, a new top-down design approach based on multi-skeleton model is proposed in this article. First, in accordance with different kinds of design parameters, three major skeleton models are defined, including location skeleton model, published skeleton model, and design skeleton model. And the characteristics of multi-skeleton models are also described. Then, the top-down design process based on the multi-skeleton model is explored, especially in the multi-skeleton modeling phase. It is also illustrated in detail that how to realize design parameter transmission and design unit reuse. Subsequently, it elaborates the communicating way and structure optimization of design parameters to support parameters controlled publishing and design units reuse. Finally, a meteorological satellite and a crawler crane design cases are implemented to expound the feasibility and effectiveness of the proposed framework.

An accurate method for the calculation of ultimate load in lattice boom

“…The braces were arranged in cross-type, and length l C between each joint was 1389 mm, as shown in Figure 5. Hence, the chord's cross-sectional area A C was 766.6 mm 2 , whose inertia moment I C was 358,074 mm 4 . The brace's cross-sectional area A B was 215.9 mm 2 , whose inertia moment I B was 20,585 mm 4 .…”

“…The ratio formulas above have shown that the chord's effective length factor is related to the length l C between joints, the chord's inertia moment I C , the lattice boom's height h or width b, and the brace's inertia moment I B . According to equation (4), the effective length factor m 1Y in the transverse plane is 0.9573, and the effective length factor m 1Z in the longitudinal plane is 0.9519.…”

“…Hence, the chord's cross-sectional area A C was 766.6 mm 2 , whose inertia moment I C was 358,074 mm 4 . The brace's cross-sectional area A B was 215.9 mm 2 , whose inertia moment I B was 20,585 mm 4 .…”

“…1,2 Therefore, the carrying capacity of lattice boom has become one of the key studies for research scholars and technical staff. 3 Chu et al 4 showed us the design and assembly process of crawler cranes, which made us more clearly know the internal structure of crawler cranes. When a crawler crane is working, lattice boom is mainly under combination of compressive and bending stresses.…”

Knowledge-based hierarchical modeling evaluation method for skeleton models

“…High-end CAD software, such as CATIA from France and CREO from America, both support skeleton modeling. They have played significant roles in the design of complex products in fields such as aerospace [1], aviation [2], shipbuilding [3], and engineering machinery [4]. Especially in aerospace, CATIA serves as the most important structure design tool for the fully digital assembly of rockets in China.…”