m，2. 1
m， 1.5
M round steel, one each. It is known that the length of each raw material is 7.4.
M, Q: How to cut materials to save raw materials?
Solution:
* * * The following five can be designed.
See the table below for the planting plan.
set up
x 1，x2，x3，x4，x5
The above are respectively
five
The quantity of raw materials to be cut in the plan. In this way, we establish the following mathematical model.
Objective function:
department
x 1
+
x2
+
x3
+
x4
+
x5
Constraints:
Science and technology.
x 1
+
2x2
+
x4
≥
100
2x3
+
2x4
+
x5
≥
100
3x 1
+
x2
+
2x3
+
3x5
≥
100
x 1，x2，x3，x4，x5
≥
The optimal blanking scheme is calculated by the software of "Management Operations Research": 30 pieces are cut according to the scheme 1; According to Scheme 2, cut 10 block; Cut 50 pieces according to Scheme 4.
that is
x 1 = 30；
x2 = 10；
x3 = 0；
x4 = 50
X5 = 0；
Only 90 kinds of raw materials are needed to manufacture 100 steel frame.
Note: when establishing this kind of mathematical model, it is better to use the sign greater than or equal to as the constraint condition than the equal sign. Because sometimes when applying some blanking schemes, there may be an extra round steel with a certain specification, but it may be the best scheme. If the equal sign is used, this scheme is not feasible.
This is an example.
Just draw a tiger according to the cat.