The Evolution of Fatigue bocks in Aluminum Alloy LY-12 under Shock beading

对LY12铝合金在低周疲劳条件下的裂纹情况和随后进行的动态拉伸条件下裂纹的发展给予了观察和统计分析。发现裂纹的累积数密度分布在损伤演化过程中保持指数形式,用NAG模型对实验结果进行分析,得出该材料裂纹演化发展方程的各种参数。

On the Evolution of Simple Shear in Saturated Soils

Development of shear bands in saturated soils is a multi-stage process based on the theoretical and numerical investigations in this paper. The soil is initially in homogenous shear strain state, and the instability can be characterized by a dimensionless number D. The inhomogenous distribution of shear strains appears when D>1, and the shear band will initiate and develop gradually. Numerical solutions show that only single shear band that is finally formed in the central region of the specimen even several disturbances (distributed along the specimen) appear in the beginning.

Characteristics and microstructure in the evolution of shear localization in ti-6al-4v alloy

A new interrupting method was proposed and the split Hopkinson torsional bar (SHTB) was modified in order to eliminate the effect of loading reverberation on post-mortem observations. This makes the comparative study of macro- and microscopic observations on tested materials and relevant transient measurement of tau - gamma curve possible. The experimental results of the evolution of shear localization in in Ti-6Al-4V alloy studied with the modified SHTB are reported in the paper. The collapse of shear stress seems to be closely related to the appearance of a certain critical coalescence of microcracks. The voids may form within the localized shear zone at a quite early stage. Finally, void coalescence results in elongated cavities and their extension leads to fracture along the shear band.

The Kaipara story: a closer look at the benefits of working together, the evolution of a federation of aquaculture self-help groups and a one-stop aqua shop in rural West Bengal

What is special about Kaipara is that most recently, they have founded a federation of Self-Help Groups that work together to develop their own support network and to draw in the support of others. This is a sophisticated ‘home-grown’ support infrastructure that is the subject of this story. (Pdf contains 8 pages).

Networking for Rural Development: a closer look at the evolution of communications in the STREAM Initiative

What began as a general desire to share messages about processes, technologies, lives and opportunities – among farming and fishing communities and those who work with them – has evolved into a network that shares meanings and lessons learnt. Now instead of relying on core funding or catalytic support, the STREAM Initiative is self-funded through the services its network provides to academic, development and other organizations. (Pdf contains 8 pages).