This paper extends the knowledge into the mechanical behaviour characterizations and constitutive modelling of polyethylene (PE) foam under multiple loading and unloading. The mechanical properties of PE foam subjected to single loading cases can be obtained by uniaxial compressive tests at quasi‐static and dynamic states. And the multiple loading and unloading behaviours of the foam can be revealed by consecutive drop tests. The major objective of this research is to propose a phenomenological model consists of shape function and modulus function, which can be predicted compressive response of PE foam for single loading cases. The constitutive models of foamed PE under multiple loading and unloading conditions are established by both using hyperbolic function, where the relations between coefficients and residual strain are introduced. And then, experiments are conducted to validate the proposed model by comparing the constitutive models proposed in this paper and those predicting by finite element software ABAQUS with those by experiments, showing that the proposed models are more accurate for predicting acceleration‐times curves of multiple drop scenarios.

The mechanical properties of molded pulp materials are the basis of the structural optimum design of molded pulp products. Therefore, the correlations between Poisson’s ratio and fiber structure, molding process, and thickness were found for materials including wood pulp, bamboo pulp, sugarcane pulp, white mixed pulp, black mixed pulp, recycled corrugated board pulp, and recycled newspaper pulp by the uniaxial tensile test and digital image correlation method. The fiber structures of the selected molded pulp materials were investigated by scanning electron microscopy. The results revealed Poisson’s ratios of wood pulp, bamboo pulp, sugarcane pulp, white mixed pulp, black mixed pulp, recycled corrugated board pulp, and recycled newspaper pulp to be 0.169, 0.108, 0.202, 0.120, 0.166, 0.098, and 0.044, respectively. Microstructural investigation further revealed that Poisson’s ratios of molded pulp materials were related to the fiber structure and drying method. The pulp material dried outside mold under lower pressure and temperature had a smaller Poisson’s ratio, while that dried inside mold under higher pressure and temperature had a larger Poisson’s ratio. The layered phenomenon of the molded pulp materials was also found by scanning electron microscopy images: the outer layer was denser than the inner layer. These results can provide guidance for the numerical simulation analysis and optimal design of molded pulp products.

Selecting a typical four-boom pump truck, the characteristics of the boom structure system and load were analyzed. The calculation model of boom structural damage was established and the calculation process was carried out based on MATLAB. In actual conditions, the strain-time signal of the four-boom structure was tested and the impact of multi-load on the boom structural damage was analyzed by decoupling method. Studies show that the strain-time history of a pump truck is a random process. It is mainly composed of two parts. One part is the overall and slow wave caused by boom posture changing. Another part is the rapid fluctuation caused by intermittent pumping. The damage caused by arm posture changing is dominant in the total damage, and the damage caused by intermittent pumping is secondary. The results reveal the composition of pump truck structure's damage. It can provide strong support for the rational formulating of fatigue test program, structure optimum design, methods selecting of structural health monitoring and safe use of pump truck.

Materials selection involves thousands of material types and evaluation parameters.Considering multisensory experience for packaging materials selection is an important trend but a difficult duty that involves uncertainty due to the subjectivity of humans. The main aim of this study is to establish a model to determine the consumer sensory experience of packaging materials as a function supporting packaging material selection development. When the consumer interacts before and after opening the packaging, vision and tactility are the foremost sensory feedback types, which are difficult to measure for fuzziness and uncertainty. Thus, given the consumer senses of vision and tactility, this paper addresses the relationship between sensory experience and packaging material properties. This is creatively formulated in three stages from the physical properties and the psycho-physical to the affective levels.The proposed approach that combines fuzzy theory and three-stage network data envelopment analysis (DEA) is used to rank 12 toning lotion bottle packaging materials. It is validated that this model allows a clear decision-making basis for material selection in packaging design, and physiological signal tests provided key data to support material selection. Moreover, it realized the function of predicting physiological signal according to material properties by backpropagation neural network (BPNN).

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