为使纬编针织物具有更真实的力学效果和体积感,在改进的弹簧-质点模型基础上对线圈进行结构建模。同时采用插值算法,在相邻型值点间插入2个新的型值点,用非均匀有理B样条曲线(NURBS)连接线圈型值点,解决了NURBS不能穿过所有型值点的问...为使纬编针织物具有更真实的力学效果和体积感,在改进的弹簧-质点模型基础上对线圈进行结构建模。同时采用插值算法,在相邻型值点间插入2个新的型值点,用非均匀有理B样条曲线(NURBS)连接线圈型值点,解决了NURBS不能穿过所有型值点的问题。为模拟股线的捻度,以此样条曲线为几何中心,用4根圆柱围绕,通过对相邻型值点的空间坐标计算3个相对欧拉角,对圆柱进行相应的旋转变换。测量了真实线圈的形变量,分析出线圈形变量与质点位移量的关系来模拟线圈变形。用Velocity-Verlet数值积分方法求解力学方程,计算各质点位移。借助于Microsoft Visual Studio 2010集成开发工具和Open GL三维绘图函数库,在计算机上实现了纬编织物的三维建模和变形仿真。展开更多
Seven kinds of weft knitted fabrics from glass fiber yarns were used as reinforcement to make fabric/epoxy composite laminates. Tensile tests were carried out to examine and compare the mechanical properties in course...Seven kinds of weft knitted fabrics from glass fiber yarns were used as reinforcement to make fabric/epoxy composite laminates. Tensile tests were carried out to examine and compare the mechanical properties in course and wale direction of these composites. On the basis of experimental results, attempts have been made to analyze some main factors influencing stress-strain curve, ultimate tensile strength and initial elastic modulus of specimens.展开更多
文摘为使纬编针织物具有更真实的力学效果和体积感,在改进的弹簧-质点模型基础上对线圈进行结构建模。同时采用插值算法,在相邻型值点间插入2个新的型值点,用非均匀有理B样条曲线(NURBS)连接线圈型值点,解决了NURBS不能穿过所有型值点的问题。为模拟股线的捻度,以此样条曲线为几何中心,用4根圆柱围绕,通过对相邻型值点的空间坐标计算3个相对欧拉角,对圆柱进行相应的旋转变换。测量了真实线圈的形变量,分析出线圈形变量与质点位移量的关系来模拟线圈变形。用Velocity-Verlet数值积分方法求解力学方程,计算各质点位移。借助于Microsoft Visual Studio 2010集成开发工具和Open GL三维绘图函数库,在计算机上实现了纬编织物的三维建模和变形仿真。
文摘Seven kinds of weft knitted fabrics from glass fiber yarns were used as reinforcement to make fabric/epoxy composite laminates. Tensile tests were carried out to examine and compare the mechanical properties in course and wale direction of these composites. On the basis of experimental results, attempts have been made to analyze some main factors influencing stress-strain curve, ultimate tensile strength and initial elastic modulus of specimens.
