中心损伤波浪参数计算用于疲劳计算时确认桩基础超单元线性化所用的波浪荷载输入。
在SACSExecutive窗口中通过Utilities>Damage center>设置选择疲劳计算文件所用单位类型>导入包含有波浪散步图定义的疲劳计算输入文件,程序就会自动根据波浪散步图的定义计算中心损伤波,计算完成后在 ‘damagecenter.output’文件中查看中心损伤波计算结果.
中心损伤波计算典型结果:
Center of Damage based on S-N Slope = 3.000 (WJ1) (中心损伤波计算所采用S-N曲线的斜率,即S-N曲线的m值为3.0)
Scatter Diagram Wave Height Units = METERS
Fatigue Case 1 (计算结果)
Foundation Linearization
Tcz = 2.339 Hcs = 8.985
Teff = 1.964 Heff = 7.996
Most Probable Maximum Wave
Tcz = 2.756 Hcs = 8.692
Tref = 3.403 Href = 16.167
(具体计算公式如下:计算时采用的的周期输入是跨零周期 Tzi,即ftginp文件中SCATD第7列定义的波浪周期如果为跨零周期,则直接采用,否则会采用下列周期转换公式转换为跨零周期后,再进行计算)
The Center of Damage Utility calculates the centroid of the scatter diagram
using the equations:
Hcs = Sum(Di Hsi) / Sum(Di) Tcz = Sum(Di Tzi) / Sum(Di)
where Di is the estimated damage of seastate i taken as Pi * (Hsi)^am / Tzi and
Pi, Hsi and Tzi are the probability of occurrence, significant wave height and
zero crossing period of seastate i, respectively.
(am,表示的是(a*m), 桩基线性化计算时a取1.8,计算可能的最大波浪时,a取1.)
(桩基线性化时,考虑有效波高和有效周期的具体参数和计算可能最大波浪时考虑有效波高和有效周期的具体参数不同。)
For foundation linearization;
In the exponent am, the term a is taken as 1.8 and m is the inverse slope of
the S-N curve. The effective wave height Heff and associated period Teff are
taken as:
Heff = 0.89 * Hcs Teff = 0.84 * Tcz
For most probable maximum wave;
The exponent term am is taken as 3.0 and the most probable maximum wave height
Href and the associated period Tref are taken as:
Href = 1.86 * Hcs Tref = Tcz / 0.81