A team of researchers from theUniversity of Chicago,Seoul National University，和California Institute of Technologyhas conducted a series of seismic experiments using 3D printed models of the Los Angeles sedimentary basin to better understand the hazards of earthquakes.
The team presented its findings at theAmerican Geophysical Union (AGU)’s Fall Meeting 2021昨天，揭示了最高的频率地震波实际上是对建筑物最具破坏性的最高地震波，实际上在模型的盆地内衰减或减少了力量，这与数值模型相矛盾，即在盆地内会放大地面摇动的数值模型。
盆地的地震建模
沉积盆地是地质结构，起源于凹陷，并且随着时间的流逝而被填满了低密度材料，例如山体滑坡和河流沉积的材料。
Earthquake-prone cities such as Los Angeles, Mexico City, and Santiago are all located in naturally occurring sedimentary basins, within which traditional numerical modeling techniques suggest ground shaking is amplified.
通常用于理解沉积盆地中的地面运动，数值建模方法通常在其空间分辨率上受到限制，并受到输入的方程式的约束。由于模型的空间分辨率和运行它所需的计算时间之间的权衡，重现数值模型中沉积盆地的小规模细节是具有挑战性的。
To address these drawbacks, University of Chicago Seismologist Sunyoung Park and her colleagues turned to 3D printed models to more rigorously investigate how seismic waves travel through sedimentary basins.
Simulating earthquakes with 3D printed models
Park and her team began 3D printing models of the Los Angeles basin after realizing they could reproduce relatively small natural variations in density within the models, corresponding to around 10 meters in size in real life. According to the researchers, the 3D printed models enabled a roughly 10 times better spatial resolution than a numerical model of the same landscape could achieve.
The team experimented with rubber and plastic materials to form the basis of their models and eventually settled on stainless steel due to its rigidity and subsequent larger range of material properties. They used an SLS 3D printing process to lay down successive layers of powdered stainless steel which was then heated and sintered together using a laser.
The team altered the printing parameters, such as the speed of the sintering laser and powder, in order to control the porosity of the model and be able to print models with a range of densities. The researchers fabricated models measuring 20 x 4 x 1 cm which captured a range of geological structures within the 50km-wide Los Angeles Basin, at a scale of 1 to 250,000.
Once the structures had been printed, the team set about conducting a series of seismic experiments to understand how seismic waves traveled through the model basin. The researchers generated tiny earthquakes by bombarding the 3D printed models with megahertz-frequency laser light. The thermal energy of the laser pulses heated the models and caused differential stresses that translated into movement.
The team recorded the ground motion at the top of the models in tenths of nanometers, and found that higher frequencies of ground motion in the models were generally reduced within basins. In fact, the seismic waves tended to be selectively reflected back at the edge of the basin.
研究结果与数值模拟前dictions that sedimentary basins are amplifiers of ground motion, leaving more areas to investigate using 3D printed models going forwards. For instance, during their experiments, the scientists also found that the laser pulses triggered airborne waves that skimmed over the top surfaces of the models. As airborne waves are heavily affected by local topography, follow-on work could include adding features like hills and mountains to the models’ surfaces and measuring how airborne waves propagate.
Further information on the study can be found in the paper titled:“Earthquakes ripple through 3D printed models of Los Angeles”,published by Eos. The study is co-authored by S. Park, C. Shin, Y. Kim, and R. Clayton.
3D打印模型应用程序
Aside from this most recent development, 3D printing has been deployed in relation to earthquakes in the past. Back in 2015, a Napa local produced a3D printed visual representation8月24日，在旧金山附近袭击了纳帕的6.0级地震的峰值地面速度（PGV）。次年，3D打印被杠杆化永生化意大利小镇Amatricein the form of an intricate model after it was struck by an earthquake that killed 297 people.
Aside from earthquakes, 3D printed models have found applications in a variety of other areas. The most prominent is anatomical models for the medical and dental sector, where 3D printing enablesfull-color realism and accuracy，启用planning of complex surgeries, andhelps patients better understand their treatment.
Elsewhere, 3D printed models have been used toaid wound dressing R&D, aid the development of治疗for infected burns, and help law enforcement officials战斗野生动植物贩运.
订阅3D Printing Industry newsletter有关增材制造中的最新消息。雷电竞充值您也可以通过关注我们来保持联系推特and liking us onFacebook.
寻找添加剂制造业的职业？雷电竞充值访问3D Printing Jobsfor a selection of roles in the industry.
Subscribe to ourYouTube channel有关最新的3D打印视频短裤，评论和网络研讨会重播。雷竞技在线登录
Featured image showsthe Los Angeles Basin imaged and mapped by NASA’s ASTER Earth-observing instrument. Photo via NASA JPL.
