ABSTRACT
With the development of the medical industry, more and more medical bed series were designed. There were different structure designs for different age levels of sickbeds. A lightweight design is an important method to reduce the cost of the large quantity production. The materials’ design of lightweight (Cho, 2009), shape and size optimization, structure optimization, and multi-objective optimization design (Leite, 2015) are the main directions of lightweight research. The weight can be reduced by 48% after applying the weight loss design for some structures (Raedt, 2014). The lightweight design of the sandwich structure can reduce weight 7.5 kg/m2 for the trailer (Michael, 2013). The lightweight design of a continuous variable cross-section roll plate is used to design the hybrid column, which makes the weight of the car reduced by about 20% (Thomas, 2015). The lightweight design method based on the impact of the car body, and the body weight can be reduced by 5.2% from the sensitivity analysis and optimization calculation to the thickness of the main structure (Lan, 2010). Lightweight structures for interior and exterior as well as car bodies, which can be produced in a flexible manner, are in the center of discussion. In order to satisfy the performance requirement of high dynamic and static characteristics and light weight of the activity crossbeam, the mass of the activity crossbeam was decreased by 12.2% through a method of multi-objective optimization (Sun, 2015). It also can reduce the structure weight by 21.4% with the improved response surface method (Pan, 2010). An arm’s model was established which supported kids’ sickbeds under the bed board by using Creo
the model of 0-1 discrete variables. At this time, the intermediate density unit corresponds to a very small elastic modulus, and the influence of the structural stiffness matrix will become very small and can be ignored. For the RAMP density stiffness interpolation model, the intermediate density of the penalty is carried out by the following equation:
E x p
=
1+ 0( )x1
where, Ei is the elastic modulus of the No. i unit. E0 is the elastic modulus of the material when the unit is filled, and p is the penalty factor.
