中文摘要：

小麦堆压缩模量是有限元模型的重要参数。采用全自动静三轴仪对小麦进行三轴压缩试验,得到小麦试样的应力-应变关系曲线,通过求导给出小麦堆压缩模量的数学表达式,分析围压对小麦堆压缩模量的影响。结果表明：小麦堆压缩模量的大小在应力-应变曲线的各个阶段是不同的。在线弹性阶段,压缩模量较小;在应力强化阶段,压缩模量达到最大值;在剪切面滑动阶段,压缩模量逐渐减小,最后降至约0 MPa;在破坏阶段,压缩模量为负值。在不同围压情况下,即使应力、应变相同,小麦堆压缩模量也是不同的。得到的小麦堆压缩模量的数学表达式,可为涉及粮食散体介质的有限元模型提供参数。

英文摘要：

The compression modulus of wheat piles is an important parameter of finite element models. We carried out triaxial compression test for a wheat sample using the automatic triaxial apparatus to obtain a stress-strain curve of the wheat sample, derived mathematical expression of the compression modulus of wheat piles, and analyzed the influences of confining pressure on the compression modulus of wheat piles. Results showed that the values of compression moduli of wheat piles were different on every stage of the stress-strain curve. The compression modulus was a small value on the linear elasticity stage, and reached a maximum value on the stress hardening stage. On the shear plane sliding stage, the compression modulus decreased to about 0MPa; and on the failure stage, the compression modulus was a negative value. Under different confining pressure, the compression moduli of wheat piles were different even under the same stress and strain. The derived mathematical expression of the compression modulus of wheat piles can provide parameters in building finite element models related to granular media of cereals.