No abstract

No abstract

No abstract

At present, biomass-based polymers can be applied in several fields, such as medicine, biology, aerospace and so on. Due to their good biodegradability, more environmentally friendly products with desirable functions can be designed and processed by people. Therefore, it can be a potential candidate to solve the serious environmental pollution caused by using petroleum-based polymeric materials in the production process. In this article, cellulose, lignin and vegetable oil are taken as examples, all of which are typical biomass-based polymer monomers, by reviewing their synthesis process and applications based on the recent studies on their production, modification and performance enhancements. The properties of final products in the industry stand out compared with many other products synthesized from petroleum-based polymeric materials as there exist different scientific modification methods to synthesize materials with desirable properties. One of the most practical applications is that all of them can be used to synthesize composite materials with enhanced properties.  However, more research is required to quantify the environmental benefits and reduce the costs of biomass-based polymers so that we can make full use of biomass-based polymers and even expand their application fields. The article analyzed the application of biomass-based polymers and proposed some suggestions for its future development to help solve the present environmental problems.

When simulating the process from elastic–plastic deformation, damage to failure in a metal structure collision, it is necessary to use the large shell element due to the calculation efficiency, but this would affect the accuracy of damage evolution simulation. The compensation algorithm adjusting failure strain according to element size is usually used in the damage model to deal with the problem. In this paper, a new nonlinear compensation algorithm between failure strain and element size was proposed, which was incorporated in the damage model GISSMO (Generalized incremental stress state dependent damage model) to characterize ductile fracture. And associated material parameters were calibrated based on tensile experiments of aluminum alloy specimens with notches. Simulation and experimental results show that the new compensation algorithm significantly reduces the dependence of element size compared with the constant failure strain model and the damage model with the linear compensation algorithm. During the axial splitting process of a circular tubular structure, the new compensation algorithm keeps the failure prediction errors low over the stress states ranging from shear to biaxial tension, and achieves the objective prediction of the damage evolution process. This study demonstrates how the compensation algorithm resolves the contradiction between large element size and fracture prediction accuracy, and this facilitates the use of the damage model in ductile fracture prediction for engineering structures.