油菜茎秆的粘弹性特性及本构关系的研究

割刀切割茎秆产生的冲击应力波传播到荚果,当应力幅值超过荚果的抗裂极限时,籽粒脱落引起收获损失.油菜茎秆的粘弹性质对应力波的传播具有很大的影响.通过测定油菜茎秆的粘性系数与弹性模量,采用三元件固体模型建立了油菜茎秆的粘弹性本掏关系,并分析了其应力、应变对时间的响应,从而得到了蠕变曲线及应力松弛曲线.为进一步研究茎秆中的应力波的传播规律,设计优化切割器参数以便减小收获损失,提供了重要数据.

Study on Viscoelastic Properties of Rapeseed Stem and the Constitutive Relationship

While stem being cut,the impact of stress wave transmission to the pod,if the stress amplitude exceeds the anti-cracking limits,loss of grain fall off.Rapeseed stalks of viscoelastic characters have great effect on the spread of stress wave.By measuring the viscosity coefficient of rapeseed stalks and modulus of elasticity,three components of solid model were adopted to establish the rapeseed stalks of viscoelastic constitutive relation.By analyzing the stress and strain response to the time,the stress relaxation curves and creep curve have been gotten which provides an important data for the further study of the propagation law of stress wave in the stem and reducing the loss of the harvest to design optimization of cutter parameters.