<> Analysis of problem one ：
first , Through fluid mechanics , structural mechanics , architecture , Material mechanics and other related knowledge , Three possible better three-dimensional foundation geometries are assumed , We analyze these three three-dimensional shapes , Choose the best , Three dimensional foundation shape that can resist the impact of tidal waves to the greatest extent , This allows sandbars to survive the impact of tidal waves for the longest time . Considering only the shape factor and the wave height of the wave, the sand castle is impacted by different directions , The actual situation of force and erosion on the front is discussed . In addition to the types of sand, the volume of sand and the ratio of water to sand, the factors that affect the destructive power of waves to sandbars are as follows , Also with the speed of the waves , The size of the spray , Angle of spray , Salinity of seawater , The angle of the beach from the horizontal , Shape of sand particles , The water absorption of sand is related to many factors . The sandcastle can be seen as a whole , It produces a deformation resistance force when subjected to impact , Then the impact part is analyzed separately , The external force of multiple sand particles , Internal support , Internal compressive stress , The dynamic equilibrium between sand and sand due to the viscous force produced by the action of water . And when impacted, a single sand particle will move due to the impact force , When the waves recede, the sand particles will be carried away by the current due to the buoyancy and tensile stress of the water , On the whole, the sand castle is preserved by the cushion of sand particles and elastic force . Due to the impact force, the shape of sand castle produces plastic deformation to adapt to the sea wave , In the next impact, the impact will be relieved .
The flow chart is as follows ：
<> Analysis of problem two ：
Different water sand ratio affects the impact resistance of sand castle , And different water sand ratio , Sand Fort foundation has different strength and elasticity , It has a different buffering capacity , Different locations of sand and sand can be known by analyzing the strength of the foundation , Some locations need better impact resistance , Some positions need better support , There are places where more tension is needed , Then you need to check every location of the sandcastle , Different water sand ratio is selected for each layer , For example, choose a lower strength in the front, but have better viscous force , It can resist more tensile stress , In the rear, water sand ratio is used to produce high strength , In order to be able to resist greater impact , Maximum impact resistance . In the process of impact , Because of the erosion of sea water , The water content and salt content in the sand castle will change , Therefore, the impact resistance of sandbars will change with the impact , The impact resistance of sand castle is a dynamic model .
<> Analysis of question 3 ：
When the sand fort has the best shaped abutment and it rains , At this time, the sand castle is impacted by the wave on the front side of the sand castle , The impact of rain on the top of the sandcastle （ Negligible ） And the erosion effect of the flow formed by the accumulation of rainwater on the top of the sandcastle . Second, when it rains , Rainwater seeps through the top , Then the water sand ratio of sand castle will change accordingly , There will be a lot of water in the middle of the sand castle, which can not be drained out, resulting in the decline of the anti deformation ability of the middle position .