为什么会出现这个错误？

楼主，您的问题解决了吗？我在计算的时候也遇到了这个问题

在你定义钢筋的双线性材料属性语句中，比如：
TB,BKIN,2,6,2,1
TBTEMP,0
TBDATA,,4E+008,0,,,,
4E+8 为屈服应力
0 为切线模量 (理想塑性？ 可是混凝土的模量却大得多)
这个切线模量是否太小了？起码应该比混凝土的模量大一些吧？可以改为弹性模量的 0.1~1 % 试试。

下面就是我模型中材料属性定义的那部分命令流，本构模型是输入的高温下的混凝土和钢筋本构，还有相应的弹性模量和热膨胀系数都是关于温度变化的，当只加重力荷载时能够算出结果，但一加上荷载后就一直不收敛，还出现上面的那种错误，请大家帮我看看，好急呀，我下个月就要交论文了，一直都算不过，先在此谢谢啦~
/PREP7
ET,1,SOLID65
ET,2,LINK8
ET,3,MESH200
KEYOPT,1,5,0
KEYOPT,1,6,0
KEYOPT,1,7,1
KEYOPT,3,1,6
KEYOPT,3,2,0
R,1,2,0.02,0,90,2,0.02
RMORE,90,0
R,2,0.0018,0.00715
MP,DENS,1,2500
MP,DENS,2,7850
MP,DENS,3,7850
!混凝土的弹性模量与泊松比
MPTEMP
MPTEMP,,0,20,100,200,300,400,
MPDATA,EX,1,,3.45E10,3.45E10,2.82E10,2.275E10,1.80E10,1.35E10
MPDATA,PRXY,1,,0.2,0.2,0.2,0.2,0.2,0.2
MPTEMP,,500,600,700,800,900
MPDATA,EX,1,,0.90E10,0.48E10,0.226E10,1.0e9,0.448e9
MPDATA,PRXY,1,,0.2,0.2,0.2,0.2,0.2
!钢筋的热膨胀系数
MP,ALPX,3,1.4E-5
!混凝土的热膨胀系数
MPTEMP
MPTEMP,,0,20,100,200,300,400
MPDATA,ALPX,1,,0.000001,0.000001,0.00074,0.0018,0.0031,0.0049
MPTEMP,,500,600,700,800,900
MPDATA,ALPX,1,,0.0072,0.01,0.014,0.014,0.014
!普通钢筋弹性模量与泊松比
MPTEMP
MPTEMP,,0,20,100,200,300,400
MPDATA,EX,2,,2E11,2E11,2E11,1.92E11,1.83E11,1.75E11
MPDATA,PRXY,2,,0.3,0.3,0.3,0.3,0.3,0.3
MPTEMP,,500,600,700,800,900
MPDATA,EX,2,,1.66E11,1.575E11,1.49E11,1.405E11,1.32E11
MPDATA,PRXY,2,,0.3,0.3,0.3,0.3,0.3
!预应力钢筋弹性模量与泊松比
MPTEMP
MPTEMP,,0,20,100,200,300,400,
MPDATA,EX,3,,1.95E11,1.95E11,1.95E11,1.84E11,1.725E11,1.61E11
MPDATA,PRXY,3,,0.3,0.3,0.3,0.3,0.3,0.3
MPTEMP,,500,600,700,800,900
MPDATA,EX,3,,1.5E11,1.39E11,1.28E11,1.17E11,1.05E11
MPDATA,PRXY,3,,0.3,0.3,0.3,0.3,0.3
!普通钢筋本构模型
TBDE,BKIN,2,,,
TB,BKIN,2,6,2,1
TBTEMP,0
TBDATA,,4E+008,0,,,,
TBTEMP,20
TBDATA,,4E+008,0,,,,
TBTEMP,300
TBDATA,,4E+008,0,,,,
TBTEMP,400
TBDATA,,3.24E+008,0,,,,
TBTEMP,500
TBDATA,,2.48E+008,0,,,,
TBTEMP,700
TBDATA,,0.96E+008,0,,,,
!预应力钢筋本构模型
TBDE,BKIN,3,,,
TB,BKIN,3,6,2,1
TBTEMP,20
TBDATA,,1.86E+009,0,,,,
TBTEMP,100
TBDATA,,1.86E+009,0,,,,
TBTEMP,300
TBDATA,,1.3503E+009,0,,,,
TBTEMP,400
TBDATA,,1.0105E+009,0,,,,
TBTEMP,500
TBDATA,,6.7067E+008,0,,,,
TBTEMP,600
TBDATA,,3.3086E+008,0,,,,
!输入混凝土不同温度下的本构模型,多线性随动强化（MISO）
TBDE,MISO,1,,,
TB,MISO,1,11,13,0
TBTEMP,0
TBPT,,0.0002,6.90E+006
TBPT,,0.0004,1.17E+007
TBPT,,0.0005,1.42E+007
TBPT,,0.0006,1.65E+007
TBPT,,0.0008,2.07E+007
TBPT,,0.001,2.43E+007
TBPT,,0.0016,3.11E+007
TBPT,,0.002,3.24E+007
TBPT,,0.0025,3.24E+007
TBPT,,0.0033,3.24E+007
TBTEMP,20
TBPT,,0.0002,6.90E+006
TBPT,,0.0004,1.17E+007
TBPT,,0.0005,1.42E+007
TBPT,,0.0006,1.65E+007
TBPT,,0.0008,2.07E+007
TBPT,,0.001,2.43E+007
TBPT,,0.0016,3.11E+007
TBPT,,0.002,3.24E+007
TBPT,,0.0025,3.24E+007
TBPT,,0.0033,3.24E+007
TBTEMP,100
TBPT,,0.0002,5.64E+006
TBPT,,0.0004,1.01E+007
TBPT,,0.0005,1.29E+007
TBPT,,0.0008,1.90E+007
TBPT,,0.001,2.23E+007
TBPT,,0.0015,2.84E+007
TBPT,,0.002,3.17E+007
TBPT,,0.0024,3.24E+007
TBPT,,0.003,3.24E+007
TBPT,,0.006,3.24E+007
TBPT,,0.010,3.24E+007
TBTEMP,200
TBPT,,0.0002,4.55E+006
TBPT,,0.0004,8.70E+006
TBPT,,0.0005,1.06E+007
TBPT,,0.0008,1.59E+007
TBPT,,0.001,1.89E+007
TBPT,,0.0015,2.59E+007
TBPT,,0.0020,2.93E+007
TBPT,,0.0025,3.16E+007
TBPT,,0.0030,3.237E+007
TBPT,,0.0040,3.237E+007
TBPT,,0.0050,3.237E+007
TBPT,,0.0010,3.237E+007
TBTEMP,300
TBPT,,0.0002,3.60E+006
TBPT,,0.0004,6.93E+006
TBPT,,0.0005,8.51E+006
TBPT,,0.001,1.725E+007
TBPT,,0.0015,2.12E+007
TBPT,,0.002,2.56E+007
TBPT,,0.003,3.08E+007
TBPT,,0.0038,3.20E+007
TBPT,,0.005,3.20E+007
TBPT,,0.008,3.20E+007
TBPT,,0.010,3.20E+007
TBTEMP,400
TBPT,,0.0002,2.70E+006
TBPT,,0.0005,6.47E+006
TBPT,,0.0010,1.21E+007
TBPT,,0.0015,1.68E+007
TBPT,,0.002,2.08E+007
TBPT,,0.003,2.65E+007
TBPT,,0.0035,2.83E+007
TBPT,,0.004,2.95E+007
TBPT,,0.0048,3.022E+007
TBPT,,0.0048,3.022E+007
TBPT,,0.006,3.022E+007
TBPT,,0.008,3.022E+007
TBPT,,0.010,3.022E+007
TBTEMP,500
TBPT,,0.0002,1.80E+006
TBPT,,0.0005,4.35E+006
TBPT,,0.0008,6.74E+006
TBPT,,0.001,8.23E+006
TBPT,,0.002,1.47E+007
TBPT,,0.003,1.94E+007
TBPT,,0.004,2.26E+007
TBPT,,0.005,2.45E+007
TBPT,,0.006,2.51E+007
TBPT,,0.008,2.51E+007
TBPT,,0.010,2.51E+007
TBTEMP,600
TBPT,,0.0005,2.40E+006
TBPT,,0.001,4.61E+006
TBPT,,0.002,8.40E+006
TBPT,,0.003,1.14E+007
TBPT,,0.005,1.54E+007
TBPT,,0.006,1.64E+007
TBPT,,0.0074,1.69E+007
TBPT,,0.008,1.69E+007
TBPT,,0.010,1.69E+007
TBTEMP,700
TBPT,,0.0005,1.13E+006
TBPT,,0.001,2.20E+006
TBPT,,0.002,4.05E+006
TBPT,,0.003,5.62E+006
TBPT,,0.004,6.91E+006
TBPT,,0.005,7.92E+006
TBPT,,0.006,8.68E+006
TBPT,,0.007,9.21E+006
TBPT,,0.008,9.51E+006
TBPT,,0.009,9.61E+006
TBPT,,0.010,9.61E+006
TBTEMP,800
TBPT,,0.0005,5.0E+005
TBPT,,0.001,9.71E+005
TBPT,,0.002,1.82E+006
TBPT,,0.003,2.57E+006
TBPT,,0.004,3.2E+006
TBPT,,0.006,4.17E+006
TBPT,,0.008,4.77E+006
TBPT,,0.0108,5.06E+006
TBPT,,0.020,5.06E+006
TBTEMP,900
TBPT,,0.0005,2.24E+005
TBPT,,0.001,4.15E+005
TBPT,,0.002,8.3E+005
TBPT,,0.004,1.49E+006
TBPT,,0.006,1.99E+006
TBPT,,0.008,2.34E+006
TBPT,,0.0128,2.67E+006
TBPT,,0.020,2.67E+006
TB,CONC,1,1,9,
TBTEMP,0
TBDATA,,0.5,1,3.42E6,-1,,

材料的非线性熟悉定义有问题，据其算出的材料切线矩阵不正确，可能是屈服应力值太小。
首先你应该把自己的具体问题说得详细一些，别人才好帮你分析。
请你把你定义的材料具体属性数据发上来看看。

freemodel能说的再详细点吗？我看那错误好像是材料本构关系出问题了呀……