Blow Up and Global Existence for a Nonlinear Viscoelastic Wave Equation with Strong Damping and Nonlinear Damping and Source terms ()
1. Introduction
A purely elastic material has a capacity to store mechanical energy with no dissipation (of the energy). A complete opposite to an elastic material is a purely viscous material. The important thing about viscous materials is that when the force is removed it does not return to its original shape. Materials which are outside the scope of these two theories will be those for which some, but not all, of the work done to deform them can be recovered. Such materials possess a capacity of storage and dissipation of mechanical energy. This is the case for viscoelastic material. The dynamic properties of viscoelastic materials are of great importance and interest as they appear in many applications to natural sciences. Many authors have given attention to this problem for quite a long time, especially in the last two decades, and have made a lot of progress.
In [1] , Messaoudi considered the following initial-boundary value problem:
(1.1)
where
was a bounded domain of
with a smooth boundary
,
, p > 2, and
was a positive nonincreasing function. He proved a blow up result for the solution with negative initial energy if
, and a global result for
. This result was later improved by Messaoudi [2] , to certain solutions with positive initial energy. A similar result was also obtained by Wu [3] using a different method.
For the problem (1.1) in
and with
, concerning Cauchy problems, Kafini and Messaoudi [4] established a blow up result for the problem
(1.2)
where
satisfied
and the initial data were compactly supported with negative
energy such that
.
In the absence of the viscoelastic term
, the problem has been extensively studied and results concerning existence and nonexistence have been established. In bounded domains, for the equation
(1.3)
,
,
, it is well known that, for
, the source term
causes finite time blow up of solutions with negative initial energy (see [5] ). In contrast, for
, the damping term
assures global existence for arbitrary initial data (see [6] ). The case of linear damping
and nonlinear source has been first considered by Levine [7] [8] . He showed that solutions with negative initial energy blew up in finite time. Furthermore, the interaction between the nonlinear damping
and the source terms was studied by Georgiev and Todorova [9] , for a bounded domain with Dirichlet boundary conditions. For the same problem, Messaoudi [10] extended the blow up result to solutions with negative initial energy.
In [11] , Berrimi and Messaoudi considered
(1.4)
in a bounded domain and
. They established a local existence result and showed that the local solution was global and decays uniformly if the initial data were small enough.
In [12] , Song and Xue considered with the following viscoelastic equation with strong damping:
(1.5)
where
was a bounded domain of ![]()
with a smooth boundary
,
,
, and
was a positive nonincreasing function. They showed, under suitable conditions on
, that there were solutions of (1.5) with arbitrarily high initial energy that blow up in a finite time. For the same problem (1.5), in [13] , Song and Zhong showed that there were solutions of (1.5) with positive initial energy that blew up in finite time. For more related works, we refer the reader to [14] - [18] .
In this work, we intend to study the following initial-boundary value problem:
(1.6)
where
is a bounded domain with a smooth boundary
,
, p > 2,
,
,
for the problem (1.6), the memory term
(see [19] [20] ) replaces
,
and we consider the strong damping term
and the nonlinear damping term
.
Now, we shall add a new variable
to the system which corresponds to the relative displacement history. Let us define
(1.7)
A direct computation yields
(1.8)
Thus, the original memory term can be written as
(1.9)
and we get a new system
(1.10)
(1.11)
with the initial conditions
(1.12)
and boundary conditions
(1.13)
The paper is organized as follows. In Section 2, we first prove the blow up result, and then in Section 3, we prove the global existence result.
For convenience, we denote the norm and scalar product in
by
and
, and let
.
denotes a general positive constant, which may be different in different estimates.
2. Blow Up
In this section, we present some materials needed in the proof of our results, state a local existence result, which can be established, combining the argument of [21] , and prove our main result. For this reason, we assume that
(G1)
is a differentiable function satisfying
;
(G2)
;
(G3) There exists a constant
such that
,
;
We start with a local existence theorem which can be established by the Faedo-Galerkin methods. The interested readers are referred to Cavalcanti, Domingos Cavalcanti and Soriano [22] for details:
Theorem 2.1. Assume (G1) holds. Let
and
(2.1)
Then for any initial data
,
with compact support, problem (1.10) has a unique solution
![]()
for some
.
Lemma 2.2. Assume (G1), (G2), (G3) and (2.1) hold. Let
be a solution of (1.10), then
is nonincreasing, that is
. (2.2)
where
. (2.3)
Proof. By multiplying the Equation in (1.10) by
and intergrating over
, we get
(2.4)
For the fourth term on the left side (2.4), by using (1.11), (G2) and (G3), we have
(2.5)
where
(2.6)
Then, we obtain
(2.7)
So, we have
(2.8)
where
![]()
Our main result reads as follows.
Lemma 2.3. Suppose that (2.1) holds. Then there exists a positive constant
such that
(2.9)
for any
and
.
Proof. If
, by Sobolev embedding theorem Young’s inequality, then we have
![]()
So, we obtain
![]()
If
, then
![]()
Therefore (2.9) follows.
We get
(2.10)
and use, throughout this paper, C to denote a generic positive constant.
As a result of (2.3) and (2.5), we have
Corollary 2.4. Suppose that (2.1) holds. Then, we have
(2.11)
for any
and
.
Lemma 2.5. (
inequality) Let a, b is arbitrary real, then we have
(2.12)
where
(2.13)
Proof. We set
, that is to proof
![]()
By taking a derivative of
, we obtain
![]()
If
, then we know
is monotone decreasing on
and monotone increasing on
, and
![]()
Then, we have
![]()
If
, then we know
is monotone increasing on
and monotone decreasing on
. So, we have
![]()
The proof is completed.
Next, we have the following theorem concerning blow up.
Theorem 2.6. Assume (G1), (G2), (G3) and (2.1) hold. Let
,
satisfy (2.1). Assume further that
(2.14)
if
and satisfy
, then the solution of problem(1.10)blow up in finite time.
Proof. From (2.2), we have
(2.15)
consequently, we have
(2.16)
Similar to [18] , then we define the weighed functional
(2.17)
where
shall be chosen in what follows. Let
(2.18)
By multiplying (1.10) by
and taking a derivative of (2.17), we obtain
(2.19)
By using Holder inequality and Young’s inequality to estimate the fourth term on the right hand side of (2.19)
(2.20)
for some number
with
. From (2.3) we have
(2.21)
Then, we have
(2.22)
that is
(2.23)
By using Holder inequality and Young’s inequality to estimate the last two terms on right hand side of (2.24), we obtain
(2.24)
and
(2.25)
and
(2.26)
Substituting (2.24), (2.25) and (2.26) and to (2.23), we have
(2.27)
by taking
so that
, so
, for large K to be specified later, and substituting in (2.28) we obtain
(2.28)
by taking proper
,
,
such that
(2.29)
so, we have
(2.30)
From (2.16), we have
(2.31)
Then, hence (2.31) yields
(2.32)
where
,
, and taking proper
,
,
such that
,.
Writing
, for
, we know
. By using Corollary2.4 we have
(2.33)
where
.
From (2.3) and (G1) we have
(2.34)
writing
, where
, estimate (2.34) yields
(2.35)
at this point, we choose
large enough, so
is small enough. Then there exists
such that
. (2.36)
By using Holder inequality and Young’s inequality, we next estimate
(2.37)
and
(2.38)
which implies
(2.39)
where
, we take
, to get
by (2.18). We then use Corollary 2.4
(2.40)
By using
inequality we have
(2.41)
According to (2.36) and (2.41), we get
(2.42)
where
. According to the theorem of Ordinary Differential Equation, we have
(2.43)
So, we know
blow up in finite time
. The proof is completed.
3. Global Existence
In this section, we show that solution of (1.10) is global if
.
Lemma 3.1. For
,
,
is the convexity of the function.
Proof.
,
so,
is convex.
Theorem 3.2. Assume (G1), (G2) and (G3) hold. Let
satisfy (2.1). If for any initial data
with compact support, so problem (1.7) has a unique global solution, such that
![]()
for any
.
Proof. Similar to [23] , we set
(3.1)
from (2.3), we have
(3.2)
By differentiating
and using (2.2), we get
(3.3)
By using Holder inequality and Young’s inequality, we next estimate
(3.4)
Setting
, we know
is the convexity of function by Corollary 3.1. Since 2 < p ≤ m, we obtain
(3.5)
Substituting (3.5) to (3.3), we have
(3.6)
so, there exist a small enough constant
such that
(3.7)
Then, by using Gronwall inequality and continuation principle, we complete the proof of the global existence result.
Acknowledgements
The authors express their sincere thanks to the anonymous reviewer for his/her careful reading of the paper, giving valuable comments and suggestions. These contributions greatly improved the paper.
This work is supported by the National Natural Sciences Foundation of People’s Republic of China under Grant 11161057