Intrinsic, thermal and hygroscopic residual stresses in thin gas-barrier films on polymer substrates

Intrinsic, thermal, and hygroscopic contributions to the in-plane residual stress in silicon nitride films on polyimide substrates are identified, based on iso-hygric thermal ramps and isothermal relative humidity jumps, combined with non-linear elastic modeling of the resulting dynamics of film curvature. This approach enables the thermal and hygroscopic properties of thin nitride films to be determined and provides useful input for material and process control.     

误读与纠正

分析材料试验机度盘偏转角度小 (准确度低 )、试样打滑、定义 (上屈服强度 -下屈服强度 -屈服强度 )模糊、不同应力速率等导致误读 ,并针对误读原因提出纠正方法。     

连续箱梁桥中跨合龙段劲性骨架优化设计

结合某连续箱梁桥悬臂施工实践,对中跨合龙段劲性骨架设置和受力进行了分析,推导了劲性骨架设计的理论计算公式,并分析了劲性骨架刚度大小对桥梁整体结构的影响。     

静载荷和疲劳载荷作用下 C/Al 正交层压板的力学响应

本文讨论静载荷及疲劳载荷作用下 C/Al 正交层压板的力学响应,并考虑损伤过程中的临界现象,以此作为结构设计准则的基础。对静载荷作用的情况:(1)90°铺层的门槛应变ε_(FPF)随着约束程度增加而增加,而且开裂后的行为也受约束程度的影响。(2)经历加载-卸载再重新加载至断裂的过程后,初始试样存在一个剩余永久变形,其损伤状态可以用刚度的变化来表征;而疲劳试样在加载-卸载过程中刚度变化很小,反映其损伤达到一个稳定的状态。对疲劳载荷作用的情况:(1)对于给定的应力比 R,试样会趋于与它所承受的 S_(max)最大值相应的 SDS 状态。循环应力范围的不断增大,会引起基体损伤的增加,从而重新建立新的饱和损伤状态。(2)对于每一损伤状态均有一对应的循环应变范围 Δε。在 SDS 状态下,Δε保持不变。(3)以刚度下降为损伤参数对 C/Al 层压板进行了降级应力分析,并由此来预计在ΔS_(sh)以下,层压板不会发生疲劳损伤累积。     

以应力分析为基础的汽包封头强度计算

本文介绍应力分析设计法的原理，通过有限元计算得到汽包封头的温度场、应力场，并以应力分析为基础对汽包封头强度作了校核。     

Scattering of waves by flaws in anisotropic laminated plates

The strip element method (SEM) is used to investigate wave scattering by rectangular flaws in anisotropic laminated plates. The plates containing flaws are divided by junctions into domains in which the SEM is applied. For each domain, SEM equations are obtained which give a relationship between the traction and displacement vector on the vertical boundaries. A set of equations which gives a relationship between the traction and displacement vector on the junctions is then obtained by assembling the SEM equations for all the domains. This set of equations is solved by using the conditions on the junctions. Scattered wave fields in the frequency domain for isotropic and composite plates with rectangular flaws are computed and discussed in comparison with results for corresponding plates without flaws. A technique for determining the length of a rectangular flaw in a plate is also presented. The results presented in this paper are of importance and could be used in the characterization of flaws in anisotropic laminated plates.     

激光散斑干涉法测定干涉螺接孔边应力分布

本文提出一种测量孔边干涉螺接应力分布的新实验方法,用激光散斑干涉技术测量出由干涉螺接应力形成的孔周位移场分布,进而确定孔这应力分布,在保证测量精度同时,该方法体现出了简单,实用,有效等优点。     

铸造合金凝固过程瞬时应力的测试

以计算机采集处理系统为手段,测试了应力框铸件凝固过程的瞬时应力.结果表明,该方法简便、速度快,精度高,可获得铸件凝固过程瞬时应力及温度的动态变化过程。     

压力传感器的应力计算

从弹性力学的板壳理论出发,对不同参数的凸型板结构形变膜受压后的应力分布作了近似计算,为高线性度SOI压力传感器的芯片设计提供了理论指导。用BESOI技术研制的凸型板结构集成压力传感器的非线性度达0 09%,样品灵敏度的实测值与应力计算理论值的差别约17%。     

羊皮服装革的弯曲应力松弛性能及其与(手感)弹性之关系研究

本文研究了羊皮服装革的弯曲应力衰减性能。对应力衰减常数（αｂ）及其与羊皮服装革手感弹性的关系进行了讨论。结果表明：αｂ与革的手感弹性相关。αｂ值定量反映出革的手感弹性优劣。