tube hydroforming (thf) process is used to produce the complex components from the initial cylindrical tubes. in this paper, t- shape component was formed using a tube hydroforming machine and the residual stresses of hydroformed tube was determined by hole drilling method. subsequently, the thickness distribution and residual stresses of final tube were investigated using experimental and fini...

Underground engineering construction is facing increasingly complex geological conditions and challenges, such as surrounding rock deformation lining cracking, that seriously threaten the safety of tunnel operation. Aiming at these problems, a pipeline crossing jointed expansive mudstone strata was taken an example, disaster characteristics were analyzed through field investigation. The disaste...

The World Stress Map (WSM) project has compiled a global database of quality-ranked data records on the contemporary tectonic stresses in the Earth’s crust. The WSM 2005 database release contains approximately 16 000 data records from different types of stress indicators such as earthquake focal mechanisms solutions, well bore breakouts, hydraulic fracturing and overcoring measurements, as well...

Wellbores drilled in igneous formation with weak interlayers face significant risk of instabilities. This study aims to investigate the underlying mechanisms these instabilities by employing a combination rock mechanics tests and numerical simulation techniques. The mechanical properties rocks are evaluated determine core strength parameters analyze impact drilling fluid immersion on strength. ...

In order to solve the problems of roadway stability and easy instability under repeated mining close-distance coal seam groups, mechanism control technology surrounding rock were studied via indoor testing, field physical similarity simulation experiment, numerical simulation. The results show that has low strength, bearing capacity, poor self-stabilization ability, it is vulnerable engineering...

to assess seismic hazard, it is essential to estimate the potential seismicity, particularly estimation of size of the largest earthquake that can be identified by a distinct fault or earthquake source. one of the methods applied to estimate magnitude of earthquake is use of empirical relationships between magnitude and fault parameters. fault parameters for the earthquakes from early instrumen...

Horizontal gene transfer is accepted as an important evolutionary force modulating the evolution of prokaryote genomes. However, it is thought that horizontal gene transfer plays only a minor role in metazoan evolution. In this paper, I critically review the rising evidence on horizontally transferred genes and on the acquisition of novel traits in metazoans. In particular, I discuss suspected ...

To mitigate carbon emissions during the construction of deep foundation pit support in undulating strata, a theoretical calculation approach was utilized to design and compute for Qingdao’s Metro Line 4. On this basis, numerical simulation method is used optimize scheme with surface deformation stress structure. The results show that final ground settlement 5.26 mm, maximum horizontal displacem...

background: cervical spine sustains most of thevertebral column injuries, among other injuries, the disc degeneration and damage that lead to replacement of the damaged disc with cage or artificial disc. methods: the c4 to c6 vertebrae of a normal subject and a person with interbody fusion cage were 3d modelled and then analyzed using finite element method. the results of maximum stress and str...