106
4 Structure and Mechanism Technology of Lunar Lander
verification in phase C, design, manufacture, acceptance, test of flight hardware and
operation after launch in phase D and E.
The major function of lunar lander structure was to provide platform for equipment installation and bearing load, i.e. to provide surface and room for equipment
installation onboard lunar lander, as well as to ensure accuracy of equipment installation surface and integrity of configuration during ground operation, launch, landing
and operation on lunar surface.
4.3.1 Structural Design
1. Determination of Requirements for Structural Design
Before structural design, it was necessary to define requirements. Trade-off and
comparison of different options was the key to optimal design that meets the
requirements.
For the design of the lander structure, although a number of specific requirements
existed, it could be summarized as “The structure shall support operation of the
instruments on board lunar lander with sufficient strength, stiffness, and accuracy.”
The structural design usually began with the primary structure, taking into account
the strength and stiffness of the structure. These requirements came from configuration of lunar lander, mass property, launch loads, landing impact and fundamental
frequency limitations.
The primary structure was the framework of lunar lander which was usually made
up of a primary body, interface ring with launch vehicle, and support structure for
landing legs. Typical requirements for primary structure design are listed in Table 4.1
[15].
For the special impact load to lunar lander structure, due to cushion effect of
landing cushion mechanism, the load on support structure for landing legs could be
treated as static load, except that the load transfer path of landing impact load on the
structure was different from that of launch load. The response of onboard instruments
due to landing impact could be treated as a sinusoidal vibration response.
2. Structural Configuration Design
The configuration design of lunar lander was the basis of the structural design. The
structural design could only be initiated after completion of the configuration design.
The system scheme, especially the configuration scheme, had a great influence on
the structural scheme. The structural design requirements should be derived from
the system configuration. Therefore, joining the system configuration design was a
good starting point for the structural design.
In order to make the structural design more reasonable, the force transfer path was
an important issue in the configuration design. The principle of force flow continuity
and the shortest direct transfer path were the basic principles of structural design. A
rationally designed force transfer path could provide higher structural rigidity with
less structural material and make strength design easier.
4 Structure and Mechanism Technology of Lunar Lander
verification in phase C, design, manufacture, acceptance, test of flight hardware and
operation after launch in phase D and E.
The major function of lunar lander structure was to provide platform for equipment installation and bearing load, i.e. to provide surface and room for equipment
installation onboard lunar lander, as well as to ensure accuracy of equipment installation surface and integrity of configuration during ground operation, launch, landing
and operation on lunar surface.
4.3.1 Structural Design
1. Determination of Requirements for Structural Design
Before structural design, it was necessary to define requirements. Trade-off and
comparison of different options was the key to optimal design that meets the
requirements.
For the design of the lander structure, although a number of specific requirements
existed, it could be summarized as “The structure shall support operation of the
instruments on board lunar lander with sufficient strength, stiffness, and accuracy.”
The structural design usually began with the primary structure, taking into account
the strength and stiffness of the structure. These requirements came from configuration of lunar lander, mass property, launch loads, landing impact and fundamental
frequency limitations.
The primary structure was the framework of lunar lander which was usually made
up of a primary body, interface ring with launch vehicle, and support structure for
landing legs. Typical requirements for primary structure design are listed in Table 4.1
[15].
For the special impact load to lunar lander structure, due to cushion effect of
landing cushion mechanism, the load on support structure for landing legs could be
treated as static load, except that the load transfer path of landing impact load on the
structure was different from that of launch load. The response of onboard instruments
due to landing impact could be treated as a sinusoidal vibration response.
2. Structural Configuration Design
The configuration design of lunar lander was the basis of the structural design. The
structural design could only be initiated after completion of the configuration design.
The system scheme, especially the configuration scheme, had a great influence on
the structural scheme. The structural design requirements should be derived from
the system configuration. Therefore, joining the system configuration design was a
good starting point for the structural design.
In order to make the structural design more reasonable, the force transfer path was
an important issue in the configuration design. The principle of force flow continuity
and the shortest direct transfer path were the basic principles of structural design. A
rationally designed force transfer path could provide higher structural rigidity with
less structural material and make strength design easier.